Dictatorship is very easily overthrown!!
Institutional socialism can not defeat ingrained capitalism and no amount of dictates and decrees will actually make people be socialist!!
The problem with dictatorship is A) it's oppressive, everyone understands this and there's no point in arguing over it, B) it's useless.
Even democratic dictatorships collapse given time, look at Thatcherism, in Britain documentaries like "Workers at War", showing how various workers have all attempted to stave of the attacks and control of management, have made it onto the screen. This is a definite shift in hegemony and culture, in the Thatcher years shows that either overtly or covertly encouraged yuppie living and rabid nationalistic anti-communism where invogue.
Look at the little things gradual change with real permanence is far better than the most provisional revolution and every institutional revolution is provisional should it last ten minutes, ten years or longer.