Sonic Adventure introduced a lot of the problems with modern Sonic
Some of them weren't that bad back then since it was the first of its kind.
characters
Except this trend started with Sonic 2.
deep plots
(partially joking)
But we loved it... If we hadn't and we made a big stink like people did with Sonic 06 or Sonic 4 then they'd have quickly realized their mistake and changed it back ASAP.
That's because:
1. It was the first full 3D Sonic game
2. The gameplay was considered mostly good for the standards of the time it was released
3. people weren't traumatized by what came afterwards.
But it was the Sonic fans that continued to (and still continue to) push for Sonic Adventure 3 with all of its terrible faults.
I don't think people wanting Sonic Adventure 3 want it to have the same camera and control problems of the originals.
But this is why we have had these things for so many years, there are tons of Sonic fans that genuinely enjoy the things that others hate.
Unfortunately, we can't do anything about that. And there's nothing really wrong with that, except when they act crazy about it.
When it comes to wanting a Sonic Adventure 3, just because something didn't really work that well the first time doesn't mean it can't work at all.