I can't imagine they are very much fun after the first dozen questions. Promoting philanthropy to a wider audience? Bringing the spotlight on a specific cause?
Its awesome that someone as busy and important as Bill Gates is willing to take the time to do this whatever his reasons, I'm just wondering the reason why?
It's also a great way to stay connected with your base, even for someone like Bill, who is still trying to accomplish things that are easier with broad support.
Gates has, among some geeks, a really nasty reputation. It's, in fact, so bad I am not sure we can even trust the philanthropist. For me, it's just too easy to imagine him as being a supervillain. ;-)
Everyone has a dark side. His darkest side got fed and exposed while at Microsoft and he has been paying for it ever since.
I sort of see his job (what he chooses to make it anyway) as helping other people do good works by expanding their resources. I'm not sure that benefits from a 110% time commitment.