It isn't, and I think this version of the sorcerer is better for that. It has a narrative place and it states it loudly and this makes it stand out in a crowded field of character options, in a way that makes it appealingly different from anything else. It's not Generic. It shouldn't be. It's interesting, instead. Even the fighter probably shouldn't be generic, and being generic is an apparent design goal for the 5e fighter.
While 'being generic' is very clearly not a design goal for 5e classes - being mechanically distinct presumably is - there are some (sub)classes, like the fighter(BM), that stand in for a broader range of concepts than others. And, yes, arcanist is, in contrast, a heavily-served set of concepts, with 8 wizard traditions (the classic schools), the Warlock, Sorcerer, & Bard, plus EK & AT - 17 sub-classes (darn near half those in the PH) at release. I can understand needing to carefully differentiate them if they were all to be included.
I don't necessarily agree that it's 'better' to have many highly detailed, locked-in-flavor options for a genre archetype that tends to be used for exposition, plot device, and the occasional DeM. Nor do I agree that going that rout necessitates eschewing even one sub-class option that's a more generic/customizable catch-all for anything else.
And, for 5e's goals of broad inclusiveness and post-edition-war re-unification, every player who finds they can't reprise some favorite PH1-only concept from some past edition is a small, lamentable failure.
I don't want a meaningless set of mechanics that you could use to build whatever character you dreamed of, I want a role to play.
Better a meaningless set of mechanics with which I can build whatever I want than a meaningless set of mechanics that pointedly exclude the characters I'd like to
role play.
What exists now, IMO, is better than what we had in 3e, and one of the reasons it's better is because it's not just a copypaste of the wizard with a different spellcasting mechanic. It is very much its own thing.
With the same slot-based spellcasting mechanic as all other casters, and a class spell list that is unique only in having absolutely no unique spells, the Sorcerer can hardly claim to be better-differentiated than in 3e, where Spontaneous casting was a huge deal, not something yoinked by every other caster in the game. Meta-magic is cute and appropriate but not enough to hang the whole class on by itself.
That's probably at least in part because there is nothing about using a spear that says magic is in my soul and is in my essence. Using a broader selection of weapons doesn't support the narrative archetype.
Not the point, the wizard classically used only a small list of weapons, and those not too well, because of the time devoted to arcane study. Being an instinctive caster, a prodigy, was part of the Sorcerer narrative, and did imply more time available for other pursuits, thus more available weapons because he had more time to practice such things on his path to adventuring. I thought the original Sorcerer and traditional Wizard and the contrast between the two made that abundantly clear, I'm surprised you quibble with it like this.
Nah, that'd be one of those annoying choices between being effective and being flavorful.
That is exactly the kind of thing MoonSong is complaining about when she says the sorcerer 'must' be a blaster. It's not that it must be, it's just it's most nearly effective strategy, and it doesn't have a lot of flexibility to step back from it situationally. Hypothetically choosing one known spell (which, I guess you're assuming, couldn't be balanced/effective) to fit an individual concept, rather than restricting half the sub-class options to a single specific concept, isn't on nearly the same level of annoying, I'd think.
While I'd like to wild surge more often, the fact that it doesn't consume anything from me to do it is a big plus.
It's a resource-management game, you get what you pay for.

The wildmage take on the Sorcerer can be made to work, in concept, for a few less specific concepts than draconic ancestry, but the specifics do leave it less wild than some players might be looking for, and significantly more so than other concepts might call for. Player agency isn't as big a concern in 5e as system-mastery-rewarding 3e, but other classes present more opportunity for it with less trouble.
All of these are elements of the 5e sorcerer.
Sure, a Draconic sorcerer could (or the player could at least RP), some uncertainty about his heritage, in spite of having an affinity for an element and being covered with draconic scales to the tune of better protection than leather armor. It might seem a bit forced, though.
A third, less locked-in 'mystery' origin wouldn't have broken the class or ruined the game for anyone.
I think what we got was better than that, specifically because it isn't that, because that generic spellcaster is all sorts of bland.
There are plenty of non-bland arcane caster options, the existence of one more customizable one would take nothing away from them. There's no need for this assumption of exclusivity.
A sorcerer that channels magical energy through a weapon, or who fights with a mix of a weapon and magic, is yet another thing that sorcery should be able to do well, because it fits their narrative theme, but warlocks do much better.
Well, warlocks - and valor bards and EKs/ATs and magic clerics and bladesinger wizards if we want to go there.
I think, after giving everyone spontaneous casting, the designers were stuck with a basically redundant sorcerer. Rather than just tossing it as unnecessary, and loosening up another class's (warlock or wizard, I suppose) fluff-mechanics interlock to open up the same sorts of concepts, now that there wasn't a meaningful mechanical differentiation to go with it, they made metamagic (which, formerly, any caster could use, but many didn't, because it's really not that big a deal) sorcerer-exclusive and screwed down one 3e bloodline and the 2e/4e wild/chaos magic idea to the only possible sorcerers in an effort to justify having a class of that name.
I suppose they did better with it than with the ranger. And it seems like it'd be fixable - the best (recognizably D&D) fix might well be to return most casters to the more restrictive traditional Vancian casting.
BTW, "doesn't require components" is not a psionics-specific thing. If it did, Medusas and especially Beholders would be psionic, not magical. Historically, the difference between psionics and magic was primarily about the power source. Psionics is fueled entirely by yourself (effects tend to be low-energy; no AoE Fireballs, and psionic telekinesis is more likely to lift a few pounds than a thousand-pound boulder) whereas magic is fueled by an external energy source. Thus, there is no such thing as an "anti-psionics field" but there are anti-magic fields. You can't cut someone off from their self.
Medusa isn't a class or de-facto 'source' like arcanists or psionics. (And psionics has gone back and forth on being not-magic or magic.)
'No components' would be pushing it, I think, but fewer components or only one component at a time might work, possibly even flexibly. For instance, a clueless sorcerous prodigy might use his 'magic feather' but when he finally looses it, do magic by gesture instead, when he's tied up and trying to use magic, arcane phrases come to his struggling mind. It'd be the kind of inconsistent, intuitive, unpredictable magic use that drives wizards crazy.
