I stopped playing D&D with AD&D2, so can’t be sure that there is not something concrete in the D&D4 hate-fest, but my impression is that it’s only posturing. Not only from the players, but especially from TSR.
First: at the time, in D&D, nobody cared a shit about “rules”. To this day the OSR is all about “ruling, not rules”, and at the time of D&D4 (and D&D3) the general reply to any critique of a rule was “if you don’t like it change it” (with corollary “D&D is perfect, because if something doesn’t work for you, you should change it”, and “all you need is a god GM, rules are irrelevant”)
I saw the effect of this at the time of the publication of D&D3. At the time I was heavily into usenet discussions about rpgs, and one recurrent discussion was about the rules of the games I was playing (at the time, as synchronicity dictated, I was playing Ars Magica) against all the clunky bits of D&D like THAC0, decreasing armor, etc.
Then, D&D3 came out, and it removed a lot of these clunky bits, putting in a lot of bits from Ars Magica (really, in many way D&D3 was a Ars Magica hack more than a D&D one), and from one day to the other, acting as one single person, every one of the D&Dfan I was arguing with started declaring not only that these new rules were much better, but that they had always said so, and that these new rules were “the true D&D as it always was”.
At the time I finally understood that really, in D&D the rules are totally irrelevant. Nobody who plays D&D ever follow the rules in the book, anyway. It’s simply not done. The important thing is not the rules, it’ the “D&D” symbol on the cover. It’s the assurance that you are still playing “D&D”.
With the amount of ads and promotion that WotC (with MTG money) put into work at that time, you could have put a “D&D” cover on Universalis, and nobody would have blinked. They would have said “it’s the same D&D as always, look at the cover, and who cares about the rules?”
Why this did not happen with D&D4?
Maybe they wanted to be auitoironic, but the effect was insulting to a lot of players that had a firm faith into “D&D rules are perfect because all you need is a good GM”. D&D is in a lot of ways a faigh, a religion, and you NEVER make fun of people’s religions, if you don’t want to have a “holy war” declared against you.
There was a “holy war” declared against D&D4, and it had nothing to do with rules (D&D rules, to tell the truth, always sucked, any edition, any version, it’s no wonder that they say that rules are not important….), it was against the way the edition was presented and promoted. (and the 3.5 open license allowed 3.5 to survive as a kind of “I will prove my loyality to the faith by buying this” new game)