That's probably true but not at Facebook's scale. If the employees are willing to accept the argument "We could have increased profit but chose not to in the interests of users.", because everyone's bonuses and stock value is based on profit, you'd need to hire a lot of people who are happy to trade some amount of personal gain for user wellbeing. That would be difficult when you have tens of thousands of people.

Alternatively, maybe it'd be possible to run Facebook without giving the staff equity or bonuses. That would take a huge shift in the way tech renumeration works though.