I think that ultimately the problem is that Steve's successors have to fill his role of "creative asshole", but an individual with an ego as strong as Steve's simply won't get high enough in Apple to become anything close to a successor, because they'd just run into a conflict with Steve himself (and why would they even try? If you were the new Steve Jobs, would you waste time trying to get an existing corporate structure to accept you, or would you go off and start your own?)

So the people who could replace Steve are all Steve-mitations who go through the same motions, but don't actually fulfill the same role, at least if you judge by the people who come out to help with the Stevenotes. Example: Scott Forstall is crap on stage. Why? He has that stiff "I don't get to decide what I say / I am actually a tape recorder reading from Apple marketing copy" aura.

It's exactly the same problem as in that article a while ago about why Disney stopped innovating: when Walt and all the geniuses were gone, all the people who could have replaced them were instead off in places where they actually had an opportunity to do their own thing.