You don't understand investing if this is your view.

Investors like these make 100s of these investments, and expect at least 50%-75% of them to fail. If theranos was successful they'd make 100x their money back, and that's the whole point. You only need 1 or 2 of those out of 100 and you're making absolute bank.

Otherwise you think some kid walking in saying they're going to disrupt taxis and take over the ride share industry worldwide would be successful? That some kid who dropped out of Harvard has made some magic social platform that everyone will be using? All of these ideas sound stupid/unrealistic and like bad investments, but if they work they make billionaires.