Billionaire Mark Zuckerberg’s next passion is cows and beef. And to start with his passion, he has said that he is raising cows on an island in Hawaii by feeding them macadamia nuts and beer. The idea is, according to Zuckerberg, to create best beef in the world. Critics call cattle-raising project on Hawaii ranch ‘a billionaire’s strange sideshow’ and bad for the environment.
Pretty benign as far as billionaire hobbies go.
The rest seem to want to run their own private space programs or worse, meddle in politics.