Hey, don't forget that Paul Allen left Microsoft with cancer. Once he went into remission, he didn't go back to work, he decided to take care of himself and put his billions to use. Pretty easy decision, IMO.

Woz never wanted to run a company, he just wanted to build stuff. (Shameless plug for Chapter 3 of Jessica's book, Founders at Work).

For every example you cite, there's probably a new story line.