Being a media company corrupts people. These companies - Facebook and others like it - are part of people's community forming process and have to confront the very real and practical problem that promoting objective truth - insofar as we have one - is unprofitable.

There isn't going to be a large social media company that reliably runs according to high-minded community principles. Not least of which because high-minded types would figure out that one company having that much power is unworkable and doomed to corruption. Sooner or later they'll optimise towards saying whatever needs to be said. And they have to satisfy too many different - opposed - communities to maintain a respect for the truth.