All one has to do is look at this thread. A single positive comment about 4e design and there's at least three counter comments claiming that none of the innovations of 4e are actually from 4e - heck
@Lanefan's trying to claim bounded accuracy as a 1e thing. And folks are having a go at me for saying AEDU is neo-Vancian casting in drag? One single positive comment about 4e, and the edition war rhetoric gets dragged out, despite the edition warriors having won nearly ten years ago.
THAT'S the pressure. That's why WotC will not stray from the mainstream ever again. The fandom has spoken. One has only to look at the reactions to the playtests. Anything that is even remotely innovative gets voted down.
Good grief, they get shouted down for making a module that wasn't just yet another kill fest.