True, but this assumes that they all wanted a different game with totally different fluff(and I'm almost positive that this isn't 100% true)...as opposed to the same game and fluff with fixes... or perhaps tweaks along the lines of Star Wars SE.
Those two concepts need splitting.
A different game; well, 3rd edition was a different game to earlier versions of D&D. Apparently some people don't have a problem with it still being D&D. Yet there are, quite clearly, people who don't think it's the same game. And having experimented with it and found that if you play 3e the way you played BECM/1e/2e then the results of your actions would not be the same, then I've plenty of sympathy for that view.
Totally different fluff; well, which fluff makes a game D&D? Because if there's one thing that's absolutely certain it is that different GMs run their homebrew campaigns with different ideas behind their setting, and that even official published settings didn't all use the same fluff. I'm perfectly happy for you to tell the Dark Sun fans, to take one example, that their game isn't D&D because the fluff is different. I just don't think they'd agree, and neither would I.
Actually, I hope most people wouldn't agree. Changing things is what GMs do, or at least did when I started playing.