I seriously think that he is at the company because he likes his job. He probably identifies strongly at the company and feels that it is his responsibility to stay with the company.
And when something doesn't come out right, he can breath a little fire (e.g. MobileMe problems a year back or so)
So, yeah, i think he's doing it cause he's a control freak who gets high off of being in charge of one of the most important tech consumer companies in the world. But to claim that he's not benefitting massively off of Apple's continued financial success is definitely not true.