There is probably something going on at Blizzard that we don't know about. In the last time we've had tons of big guys leave, and now it seems some are going over to Riot, some are joining Rob Pardo's Bonfire and some just retire.
It might be their new schedule and work ethics that've not impressed the older crowd. They did increase the WoW team by 50% so that means there's a ton of people there now, they don't have that tight community any longer. That's at least what I think might be the problem. People saying "ohh, they're just changing jobs" couldn't be more ignorant, think about how many there's been the last months and say that again, you don't have that many OGs leaving just for a new job.
No, these are probably the ones that enjoyed the laidback state Blizzard was before Legion.