He was at least partially a scapegoat, just like GC is with WoW and every lead designer everywhere is with every game. People seem to think "lead designer" means "solely responsible for every single thing that's wrong with the game" and that's just not true. Do lead designers deserve the most blame? Probably, but at the end of the day I think we also have become "spoiled" to the point where we're almost impossible to please. We have unrealistic expectations and as a result everything disappoints us. It's a really crappy way to go through life IMO.
At any rate, D3 was a mess before he was even lead designer. There's a reason that it took about a decade between Diablo 2 and Diablo 3. Blizzard clearly didn't have an exact idea of what they wanted to do with the franchise.
---------- Post added 2013-06-22 at 11:21 PM ----------
Sure it's possible. I mean, people play LoL and have thousands of hours of fun. It's extremely rare and only the best of games can deliver on it.
Besides, ~1m people got D3 for "free" through WoW's annual pass. I know a good number of these people who vocally complain about how much they hate D3. You could easily say these people expected thousands of hours of fun for "free".