What's wrong with crackpot ideas?
Why is this a crackpot idea? Hyperloop, I kind of agree there. Still, what's the harm in him pursuing crackpot ideas that never amount to anything? If I was a billionaire, I'd probably do some crackpot things too, just because I could and I don't have to worry about a bunch of money when I'll still have more than I could ever need. Isn't that better than spending all that money on art and locking it away so only I could enjoy it, or on jewels that sit in a safe all the time?
If he's spending money on pursuing crackpot ideas, he's advancing the frontiers of technology. In the pursuit of Hyperloop he's going to have to overcome a lot of technological issues. Even if he can't solve them all, and it goes nowhere, he'll solve some of them, which may be useful to other dreams.
If he launches all these satellites, and this company goes bankrupt, someone will buy this huge fleet of satellites for pennies on the dollar, and do something useful and profitable with them. A lot of jobs will be created to build/launch them, and people will be employed by the guy who buys up the fleet for cheap.