-short story, more geared to multiplayer
-dumbed down(?) gameplay
-sequel has minimal similarities for previous series.

this is actually, a more 'global' problem, not just in D3.
the reason? simple. because when business-oriented person leads a game company, it will ruined. just like what happen in games we played these 2-3 years.

because they only care about money. screw players, they will buy what we throw at them. same thing to music,film,politics, blablabla.

in the end
do they care about you hating D3? HELL NO.
do they care about you loving D3? HELL YES, IF YOU GONNA BUY THEIR NEXT EXPANSION.