> All CEOs are essentially dictators.

No, they're not. Very few are. All CEOs serve at the mercy of the voting shareholders.

In a minority of companies, all of the votes are controlled by one person. Facebook is one of those.

Zuckerberg may be able and incentivized to think long-term, but that doesn't mean his vision is a good one. He isn't infallible just because his incentives are as good for the company as they can be.

And none of that even addresses the question of whether what is good for FB's bottom line is good for society.

Yes in theory the CEO reports to the board and the board reports to shareholders. In reality shareholders have zero say over what the CEO does, regardless of the share voting structure. They get the chance once a year to rubber-stamp the CEO's board nominations and that's it.

The exception is activist shareholders who acquire enough stock to get a board seat and then start agitating for change. They tend to be short-term players: once whatever merger or spinoff or dividend they were agitating for happens they move on to the next company.