I think the Sorcerer's problem is trying to force it's square peg (I'm different than a wizard!) into the round hole (casting spells is my shtick).
A couple of angles/ways they could have gone to make the Sorcerer truly distinctive...though I admit the subclassing break up by "Origins" was a good idea, they were a bit too narrow and ultimately uninteresting.
So, the Sorcerer's mechanical "thing" that other people don't get, they are the "Points" caster, well "wizard/mage" guy. Like the Monk is the "points" fighter (or possibly cleric). The Bard is, arguably, the "points" rogue. In PF parlance, a "points" cleric/divine caster would be the "Oracle."
Sorcerer's are the "Points" arcane caster. Fine. Metamagic should have been made a bit more prominent as a "secondary" shtick, "magic tricks" other arcane casters don't get. Which they are...but the dial could have been set at, say 6 or 7 instead of 2 or 3.
So re-write of the Sorcerer, regardless of fluff should have Meta-magic as a more prominent piece of their identity.
One thing, that I am not sure I would have endorsed, but would have helped, would have been modeling the Sorcerer after the Paladin and Ranger to be the "Arcane Half-Caster" class. I, personally, think the Bard would have been better as this, but a Sorcerer could have worked -leaving the [default] Bards to its more Roguey flavor. A little armor, probably no shields, few more than just Simple weapons. That sort of stuff.
The other thing would have been to make the "Origins" not really so defining...or not defining in the way they did. Saying Draconic and Wild (and then Storm, Shadow, etc. etc...) basically tries to "point" at a direction without really granting the goods. It doesn't matter if your grandfather was a sivler dragon or if you mother gave brith during a big storm or you fell into a magic pit of Shadow energy as a child...Your backstory is yours to make. The bottom line, at the root of the 'Origins" is that they are "Ancestral": someone in your ancestry was magic or had magic or found magic, none of that matters. It matters that it's somewhere in your lineage; OR "Circumstantial" or perhaps "Situational" would be a better phrase. You were in the right place at the right time (born during a magical storm; bit by a magically radioactive spider)...or wrong place at the wrong time (bathed in a fountain of Abyssal water, bit by a magically radioactive spider) and the result of that circumstance/situation is "I GOTS MAGIC POWERS?!" which you then practice/work/figure out and develop/expand.
The theme of your magic is what matters. What is your "source"? What type of magics do you access/relate to (fire, ice, storm, shadow, mind, plants, etc... etc...) is what really defines and flavors your backstory and current character. THAT is where the PHB sorcerer with a single Sorcerer spell list kind of falls apart.
The designers began leaning in the thematic direction, first with the UA sorcerer subclasses that began piling on "Origin Bonus Spells" (a la a cleri or paladin domain/oath extra spells). That really wasn't a bad patch/fix for what they had already done.
The latter subclasses, (storm, shadow, et al) as I said, seem to point further in the "theme" direction but also then -due to the PHB framework/chassis- amount to a few minor powers on top of the blah sorcerer spell list and limited metamagics.
SO, rework the base class with more meta's. Make the subclass options a Thematic option that allows for a thematic spell list/selection. Backstory is up to the player. Are you a Shadow sorcerer because you took a bath during a shadow-plane hurricane encursion into the material world or because great-great-gran'pappy Necrosus did the nasty with a Shadow Demon and the family-in-exile has been trying to pull itself out from under his reputation of a mad evil shadow-wizard that almost destroyed the kingdom ever since?
Does it matter to what your character can/should be able to do? No. What matters as a sorcerer is you accumulate Sorcery Points, gain more Metamagics, and have spells and abilities that are "Shadow plane" related...That probably means some illusions, some conjurations (of shadow monsters), maybe "misty-stepping" only in-out of/through shadows, making shadow-stuff weapons/shields/armor/items, transforming yourself into a Shadow or planeshifting into the Shadow plane at high levels...I'd probably throw in some resistance -developing to immunity at higher levels- from necrotic and/or cold damage...possibly with a built in sensitivity/susceptibility to radiant damage.
So, yeah...what was this thread about?...Oh yeah...a rewrite of the Sorcerer needs to be more "Theme" based than "Origin" based.
I feel like it was what they were shooting for and just missed the mark there.