I think a lot of the problem is that everyone has a different view of sorcerer in their heads.
- Lots of people want a wizard without a spellbook. The problem being that's not distinct enough to be a class. But with the way wizard is written, the spellbook isn't something which can be gotten rid of.
- Lots of other people view them as conduits of 'magic' the same way a wizard learns 'magic'. Except unlike the wizard it's not fully in control, which is where the wild magic aspect comes from.
- And other people (I'm in this camp) view sorcerers as individuals who have got magic from a very specific source like dragons, celestials, or ithilids, and their magic should all be very heavily themed around that.
The trouble here is that those three all conflict with each other. A and B don't want C, because they're picturing Harry Potter or Ran al'thor. Not some guy with tentacles or dragon scales. They want 'arcane magic' rather than themed magic. But A and C don't want B, as they don't want to be turning into potted plants or ending the campaign 2ft taller than they started. And C doesn't want other themes of magic forced onto their themed caster.
In trying to scoop up so many identities of caster into a single class, sorcerer has ended up with no real identity which anyone is happy with.