Zuckerberg is a piece of shit. But he's allowed to dictate what messages are and aren't ok for his company. The simple fact of the matter is that, when rational people leave Facebook, then all that's left are the morons and they are now the customer base Zuckerberg he has to appeal to.
I feel like if we as a country improved our educational system and made ethics important in business, then Zuckerberg, Facebook, Trump, etc. wouldn't have very much power.