Sorry if I wasn't clear.

Specifically, what I was thinking about is all the homebrewing I've seen over the years. I'm gearing up to run a 3.5 game, set in generic Greyhawk and allowing basically anything out of the WotC product line for general D&D. I haven't seen a game like this but once since the 1E days.
People seem to make substantial changes and house rules to D&D in order to "fix" it and make it playable according to the needs and desires of their group. There's considerable discussion about the merits and benefits of various materials and play styles. I just haven't seen this level of discussion going on about other games.
For example, in the old
Vampire: the Masquerade, all the games were essentially run 'by the book.' There were significant gaps left in the specifics of the setting so that individuals and groups could flesh out the mysteries of the world for their own games. Groups sometimes introduced new rules elements such as new paths of Thaumaturgy or even new disciplines from time to time. But no one ever wanted to make their own clans to replace the standard vampire clans in the same way people want to refit races and classes. Combat, feeding, blood pool, backgrounds, and social abilities essentially worked across the spectrum no matter if you played in Chapel Hill, NC or Modesto, CA. I admit, this probably had something to do with how loose the rules set was. But the phenomenon extended across to other games as well, even in the current day.
What if people didn't like
Vampire the way it was written? They didn't play
Vampire at all. They didn't try to 'fix' it. Same thing with
Battletech or
RIFTS or
Star Wars or
Call of Cthulhu.
What if people don't like
D&D? Most players seem to write their own supplemental house rules and modifications to make it something that they do like than just shrug it off.