Even if you kept the culture perfectly intact, gaming itself has changed. Players expectations have changed dramatically. You'd need the same culture perfectly adapted to the changing gaming landscape which never happens.
I don't really think that the culture at the company to be equal to the culture of gaming overall to be honest.
In fact Blizzard and especially Activision aren't really well loved company by gamers. Didn't EA got the title of worst company multiple times? They probably have a decent competitor now.
Which is why there's the biannual Diablo 2 clone that flops, and the "horrible", "failed", Diablo III is on its 24th season and sold like gangbusters on consoles.
