I dont think they are overpaid ... Sure there are bad apples and failiures but you simply cant compare it to those that are very good. Buffet comes to mind with his 1 mil fixed salary and many others from Gates to the Google founders as well as the Amazon ceo who burned his own future to carry the company through the survival stages.
Those guys are entrepreneural and not what we are speaking of here. The "hired man", especially from outside, is more the topic of discussion.