That's true, but if he Zuckerberg takes actions that significantly reduce the profitability of Facebook, the stock will go down, and that stock is a significant

That's true, but if he Zuckerberg takes actions that significantly reduce the profitability of Facebook, the stock will go down, and that stock is a significant part of the currency that he pays his employees with. If salaries are cut by a third or more, people will quit and go work somewhere else.