You don't think financing your spouse education is a gamble? Who is to say you won't get divorced right after she's done? That's honorable, but at the same time a huge risk.
So if you go into a startup, you might end up with both a failed business and a divorce.
It's only tenacity, talent, and good timing that lead to Musk and Brin having the good luck to be divorced.... but successful.
Sometimes people actually love each other. I'm lucky in that regard.