We, of course, won't get that story, and will have to settle for a news cycle of the fiduciary responsibility tourettes brigade vs. the hacks who think they're John Gruber screaming at everyone to leave Steve alone.
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.
Back when Disney bought out Pixar, I made a little spreadsheet that calculated how many DIS shares Steve wound up with. Assuming that he has not sold off (or gifted) any/much since then, his DIS stock is now worth slightly more than $5B. It has a net gain of $2B since the Pixar buyout. He is doing what he is doing out of internal motivation (and certainly not because he needs the money).