Mental illness among the super-rich is a problem that doesn't get enough attention. You have these people who basically nobody can tell them they're wrong and they have all day to sit and think.

Then on the other side, these kind of people can have a LOT of impact on the world and everyone else, so when they get some kind of fleas in their head, it can be a major problem.

This is why real decentralization of political power is important. The crowd might not be the wisest, but it IS pretty stable.