I was 'attending' a 400 level course on contemporary arts at my local university and the groupthink exhibited by the students was insane. With only 7 students in the class it was intimate and dialogue based. Just for the sake of provoking actual defences and backing to viewpoints I took up a contrarian stance on damn near every topic.
Sure I was labelled a racist, bigoted close minded hoser. But the conversations were integral to proper development of critical skills. The professor told me at the end of the year that the only reason she let me remain in her class (as opposed to booting me out as I wasn't a student or qualified) was because of this generated dialogue.
No it is worse. Misinformation is killing democracy. And that's exactly where Facebook is a problem.
We sell analytics and data about people. This data is more valuable the more people there are to sell. This popularity metric will thus foster popularity contests, where inane content and disinformation is put forward. This is the problem.
I'm convinced this is the key.
However, media outlets (social or otherwise) also have a responsibility of, at the very least, not spreading stories that are demonstrably, factually inaccurate, even if it impacts their "bottom line". Naive and hopeful, I know, but there are two sides to it.