I'd disagree that 4e was far from D&D's roots. D&D evolved from miniture-based wargames, and it remains a combat-focused P&P system. In my view 4e had two primary problems: combat was complex took a long time to resolve, even by D&D's standards, and it was different to what people were used to.
I agree D&D has evolved into a different game, but it's still a lot closer to wargaming than a lot of other P&P systems, like Fate or Fiasco for example. D&D is a system that revolves around simulating party-vs-party fights in a fantasy setting, with some roleplay rules tacked onto the periphary. I felt 4e very much continued with that theme; the problem was fights in 4e were just too complex and laborious, even for a system built primarily for combat.
