No doubt some of those complaining that Tim Cook is too sedate for them want the best for Apple, as do almost all of us on this thread. But some of these criticisms call to mind the bitching of Boston sportswriters or the Tribes of Israel when Moses was on sabbatical up in the hills. It is the fate of incumbents to be sniped at by one faction or another, no matter how successful they may be.
So - I submit - if not Tim Cook, then who? Look at some notable people in the current pool of available talent: Steve Ballmer (!) (as I mentioned earlier), Scott Forstall, Thorsten Heins. Does that give us second thoughts about deposing Tim?
It begs the question of Apple's succession plans for the near and long terms. Even when Steve Jobs took extended leaves for medical treatment and Tim was appointed to act in his place, Apple kept its succession plans secret for competitive reasons. You can be darn sure that they have an up-to-date plan in place right now, and about the only thing you can bet on is that Tim is in it for a good while barring untoward events.