> Is Burning Man fun? I got the rather cynical impression that it's mostly very well off tech people and even better off finance/political people.

Why not both?

Well off tech people can have fun too. In fact, the wealthier, the more fun the event can be, because it means more ability to do cool stuff, be generous, and avoid trouble. As for tech people, an event that attracts tech people does not make it a tech event. For instance, tech people tend to enjoy metal music, and you are going to find a lot of tech people in metal festivals, but there, music is what bring people together, not tech.