I'm of the opinion that a major contributor to the "Edition Wars" was WotC's abysmal PR and advertising. It was basically aimed at people who don't like old-school DnD and was trying to convince them that they got rid of all the stuff they don't like. In the process they alienated many existing players and caused a bunch of the vitriol themselves.
I mean, really, one of their promotional videos depicted people who don't like the 4E changes as trolls. Whoever thought that was a good idea is a moron and probably shouldn't work in advertising.
They definitely could have handled it better if their PR had been more along the lines of this Design and Development article. It does a great job at clarifying why they made the changes they did.