The issue is this...
If the race is moved to the surface, if they no longer have a connection to a dark spider goddess or spider deity, if they are no longer feared and they are no longer versed in the specific Drow society... in what way are they still Drow?
Look over the Drow racial features. Every one of them is either about being adapted to living in the darkness or using dark magic to use the darkness to destroy others. None of that, none of it, would be applicable to your Always Altruistic Surface "Drow". In fact, every single thing that separates them from being just like a Wood Elf other than skin color has been completely removed by these concessions.
So you ought to just treat them as a typical Wood Elf with dark skin because that's what they really are. And it also really destroys any sense of danger, urgency or fear they previously instilled having these surface Drow hippie communes spread across the surface in such numbers that everyone is completely familiar with them. In fact, it makes the whole premise of the Drizzt books and how Drow are written in any other case purely comedic.
Nothing of the drow
race makes me think of a connection with Lolth. Their traits come from the Faerzress, a radiation that dates back to the processes that shaped Toril. You say that the drow powers don't fit Eilistraee, but why can't Darkness, Faerie Fire, or Dancing Light be used in an artful way, to embellish a dance or create beauty (Eilistraee is the goddess of beauty, moonlight, dance and song). Why aren't they fitting for ''good'' individuals (Faerie Fire and Dancing Lights are actually closer to the Dark Dancer than they are to the Spider Queen)? They're not ''evil'' in any way, they're just... light, or absence of it. Or ability to see in the dark. Absolutely no evil in them :/ (the same goes for spell resistance, levitate, zone of truth etc that ''noble drow'' had in former editions).
You seem to think that the Eilistraeeans are all well accepted and that everyone is best buddies with them, but that's not the case.
http://forgottenrealms.wikia.com/wiki/Eilistraee#Worshipers
They do have communities, but they have to forge their place, they don't get it for granted (and generally face hostility, like it happened in Raven's Bluff despite their work to help the poor of that city, just to make an example), and they are not really a lot. Also, Drow aren't defined by 1 religion or culture, just like humans or elves aren't defined by 1 single religion or culture. Drow are generally portrayed as religious (often), proud, aggressive, dangerous, wild/fun loving--that's unrelated to their deity, and the followers of Eilistraee have those traits too (yes, even dangerous).
While you claim that they're Always Altruistic, that's not true: they're people! They may work to follow her ideals, but it is difficult in practice (it shows when they are portrayed in novels). Not all of them are equal (and none of them is the same as their goddess): each of them may feel called to a particular aspect of the Dark Maiden while not truly feeling aligned with the rest, which leads to varied (and at times even conflicting) opinions among them (and some may even embrace Eilistraee and just live their life, without being Always Altruistic). Furthermore, many come from centuries of Lolthite background, and the priest(esse)s themselves find it difficult to shake off on its own--even more with the general distrust and hostility that surface dwellers hold towards the drow (not being kill on sight anymore doesn't mean that people trust them. There are regions where the Eilistraeeans are accepted, even valued--like Elventree--but that's far from the norm). Many surfacers even believe that they are but followers of Lolth trying to work deception (which sometimes actually happens), while elves generally find Eilistraee troubling, since she conflicts with their belief that the drow are to be blamed for all the tragedies of their past.
The trust of the Eilistraeeans remains very hard to gain, and mindsets and attitudes from their previous life could be carried on in some cases. For example, some priestesses that come from a Lolthite society may act harshly towards males; other priestesses (or priests) can be aggressive--or even quick to raise a sword--if a threat is perceived, or if their ritual dances are interrupted. Also, suspicious (in the Eilistraeeans' eyes) individuals who have acquired too much knowledge (like the position of an Eilistraeean community), can be caught and held for some time to make sure that such knowledge isn't used against the drow (although no violence is inflicted on them).
The Eilistraeeans also keep many traits of their race. For example, they are still religious, and their goddess plays a big role in their lives. They are proud and don't take offense or slights lightly (especially those among them who were priestesses of Lolth). They love magic, beauty, they enjoy the adrenaline of fighting and hunting, they love dance, song and many leisure activities that the Lolthite enjoy.
So, that leaves slaves to Lolth + evil/backstabbing as the only non-shared traits, which seem to be the main ones that define the drow according to you, but which are rather lackluster to define a race IMO. In short, the Eilistraeeans are very much drow, just not slaves to Lolth or evil. And they want to show that drow can build and create, not only destroy or self-destroy. They want to build an actual future for their people.
Furthermore, your reasoning could be exteneded to various races in relations with humans. In the end, most races (including the drow: think about it, Lolth's society is but a parodic exaggeration of ours) are very much human in their ways, with some particular traits (like elves having a different perception of time) that can be considered somewhat alien.
I am not arguing they need to be universally evil, but rather that they would still be steeped in their particular society with their particular norms used to people acting in particular ways regardless of whether they ultimately fall into the category of being more altruistic than selfish... Even if within a brutal lawless society, the individual's experiences are such that they decide they aren't going to backstab allies for personal gain... they have still been raised to know that allies are likely to backstab them for personal gain and take measures to avoid being backstabbed.
If you are from a society that practices slavery and torture and enacts brutally harsh punishments, as an individual you may find these things distasteful... but any chance that you would jump up and down and make a big stink about it thus making you a target would have been broken from you at a young age or you wouldn't have survived long. Either you compartmentalize these elements and either don't utilize them but find it generally tolerable when others do, or when you engage in such things you try to be more merciful, reasonable and understanding rather than embracing them with zeal.
Although, alignment is not something that usually applies well and should generally be considered at best a general tendency rather than a universal governor of all behaviors, particularly when a single alignment is applied to an entire society and much more so an entire race. Sometimes it seems all it really means is "friendly to humans=good" and "unfriendly to humans=evil", because the idea that you could have whole societies that would survive past a single generation where everyone acts altruistic all the time without regard for their own safety or survival or acts selfish and destructive all the time without fostering and enabling the success of their fellows and the next generation are both unworkable when you try to apply any reason to them.
I adressed the always altruistic part above: they work towards it (and they actually want to experience things like love, and all that they were denied) and are guided by Eilistraee, but it's difficult to adapt to the new perspective.
The thing is, some drow may very well try and simply distance themselves from their society. That's because the lolthite drow fall under the ''acts selfish and destructive all the time without fostering and enabling the success of their fellows'' category (and it has been shown many times in novels. In Ed Greenwood's TDotU it is also mentioned as one of the main reasons why drow aren't nearly as successful as they could be).
The drow don't just work evil on others, they are basically Lolth's slaves. The society built around her faith is tyrannical and stagnant in its ideals, ultimately revolving around self-denial to gain the favor of this goddess. They are told that things like love or joy are weaknesses. They literally constantly live in paranoia and fear of everyone around them, of losing their lives to someone hypothetically plotting against them at any time. They are in constant conflict with everyone, to the point where they can never freely enjoy life--as even activities like dances or parties are ''polluted'' by this bitter conflict (and all of that's canon, from 3e DotU)--and where they are in truth ever alone (since even ''friends'' are actually hated and seen with suspicion).
They are brainwashed into believeing that their only value is in their ''rank'' or in Lolth's favor, leading them to do anything to receive her appreciation, something that she will never give them. Many also have little to no control over their own life, and can't choose what to be because Lolth says that they have to become ''X'' (this emerges very well in Elaine Cunningham's drow novels). Finally, they are told that they are merely meat for Lolth, that the only way of living is to be a toy to her and eventually die for her. They can't think or speak freely, as all new ideas of any kind are drowned in the blood of their thinker/supporters.
They have stagnated and have been limited by Lolth for 10k years (her dogma has led the drow to fail many times). You can't tell me that a significant number of them hasn't got tired of this and spontaneously tried to take another way (if only a handful of super-individuals did so
, then
that would be purely comedic). Even evil individuals would be fed up with this.
The commoners also get it very bad, as they get all the downside of Lolth's BS while not getting the privilege of power or nobility. In some cities they can even be hunted ''for sport'' at times. So, there are many reasons for a drow to want to get away from all that.
I am vaguely aware of them. But that is an issue of Orcs becoming good by being changed by a definitively non-Orcish deity. Instead it is an example of them being broken and tamed by a human deity. My example would be to create a definitively good-aligned and pacifist Orcish deity to rule over the "Light Orcs". Unless I am misunderstanding and you are claiming Eldath is an Orcish deity.
The general idea tends to be that generally evil aligned humanoids do not get good aligned deities among their pantheon and typically good aligned humanoids do not get racial-exclusive evil deities (unless it is for the one evil subrace).
Actually, to be honest.... this is sillier than that.
It would be like having a group of Light Orcs who live on the surface, like the daylight and are pacifistic all aligned under one Orcish Deity who opposes Gruumish and then having that deity have a child who somehow encourages this one single group of "Light Orcs" to act evil.
You keep ignoring the whole history of Eilistraee and Vhaeraun. Seriously, if you read it, it fits perfectly in the context of the drow. They were born *before* Lolth was even banished or evil. The dark elves of Toril knew and were followers of Eilistraee and Vhaeraun even before Lolth turned her attention to that world (see
this and
this). Even if they were born after that, there's no reason why a child necessarily support the parents or be like them. Also, re: ''generally evil aligned humanoids do not get good aligned deities'' if something hasn't been done before, it should never happen? This is fantasy, it's about telling a story and crafting worlds. Deities like Eilistraee and Vhaeraun add variety and depth, and produce more opportunities to tell intriguing stories.
In the case of Eilistraee, why do you think that her concept is silly? You have this goddess who chose to give up on a life of comfort in Arvandor, and join the dark elves of Toril after her mother was banished. She did that because she had foreseen that the drow would need her hope and light, someone who could be there for them in the times to come. Then, millennia later, after Lolth became known in Toril--and after Eilistraee's followers were decimated by the elves (yep) and her power waned--when the drow were banished and shunned by the Seldarine (even the innocent ones), only the Spider Queen and other evil deities were left for them. Eilistraee however didn't give up, she chose to share their fate and be one of them, and even now she (from the wiki)
''tries her best to be a mother goddess to her people and bring them the hope of a new life. [...] She teaches and shows to the drow kindness and love, the joy and freedom of life that were taken away from them, calling them to her and singing to their hearts. [...]The goddess helps the dark elves to strengthen, grow, and flourish in a hostile surface world, in harmony with other races and free from Lolth's tyranny, protecting her faithful and aiding them in hunting, swordcraft, and other practical matters of their everyday lives.''
That's very different from what you say. Eilistraee has also been given a strong connection with the drow. She
'' sings her call to all dark elves—from the highest matron mother to the lowest male slave—sending them dreams or visions, showing them a different, better life (especially when they are close to the surface). Lolth is powerless to stop these visions, as too much interference from two goddesses could easily bring a mortal's mind to insanity. The drow definitely come to know about and "feel" the Dark Dancer at some point in their lives, but many of them either don't understand said dreams or emotions or choose to ignore, disbelieve, or reject them. Even then, while not many refuse Lolth to cleave to Eilistraee, many secretly yearn for the goddess and all that she wishes for them. In fact, it is not unusual for them to choose to spare a stricken worshiper of Eilistraee if they think that no priestess of Lolth is watching, or to fail to pass on to other drow something they might have seen of their activities, or to stop to watch a dance of Eilistraee worshipers rather than disrupting it.''
You may dislike her, and that's totally up to you, but she definitely isn't a silly concept, is iconic for the FR drow, and has been created by Ed Greenwood for his own world (she has been part of the published FR for like 26 years now, and even more of Ed's world). You don't get more fitting than that in the context of FR.