It isn't about having money, it's about control of that money. Zuckerberg doesn't "have" the money he gives to his foundation, but he still controls it, vs taxes which he wouldn't.
Better Zuckerberg than using the money to send our young men to their deaths in Afghanistan, or pay people to have kids and not work, or to have it siphoned off through fraud by government workers, or wasted by their negligence, or...