Rich people like to make money and powerful friends and politics is one of the best ways to do that, if you are rich you will inevitably be drawn towards it, look at Elon Musk, he didn't care about politics but he's now advising Trump all the same, it's just what happens, if you are rich enough you can influence decisions being made about things closely related to your billion dollar businesses, this is just how it is.

It's family business not some aristocracy, politics is hard to get in to as anything, it requires a lot of money, how many kids fallow to what they're parents do? especially if it's something as profitable as being a politician or actor or musician? if you come from nothing you have to look the part, have the right personality and also be rich and smart enough and know the right people. Why did Trump or other non-politicians people get elected then? because they're main selling point is that they outsiders come to change everything. You need to know the right people and be rich, as long as you look passable you can easily become a politician, for all those kids born in to wealth it's just incredibly easy to take that road, they're parents can help them get jobs and introduce them other people, they're name has weight, they are naturally moved in that direction and why would they resist? would you? simply put, this is part of life, many kids fallow they're parents and it's hard to get in to politics for outsiders.