I noticed in both cases complaints by fans who hated them were centered on one person. But we, consumers, have no ideas about hwhat happen in the company. When a developer makes a wrong choice, how can we be sure he does it on its own, and that he hasnt been pressured by the Publisher, the marketting department,etc?
For Diablo 3, Jay Wilson focused all the hate, i myself must say i blame blizzard for a ton of décisions they made about this, but i dont think a single person is responsible for messing everything.
In the world of cinema, sometimes some scenarists are forced to change the ending if they want to have their movie produced.
A lot of people pointed out Lords of Shadow was made by someone who didnt give a fuck about Castlevania. But hasnt been this done for purpose? If you look at diablo story you may say the same thing, for different reasons.
My feeling is that complaints are often headed around one specific person in the company who has a twitter account and uses it a lot(for example), but that this is the tree hidding the forest.
Look how Silent hill changed. I think both games were victim of the strategy that consists in giving the development to an external studio to reduce costs. Silent hill obviously had less luck.
Sadly, this strategy can work, at least on a short termist view. But i see it as a kind of double edged sword,making a content targetting everyone can bring you more sales, but when the hype is over, if fans are disappointed, you may loose your most faithful audience.