But why is propaganda your preferred option over traditional content moderation? I doubt many people would considering it controversial to censor calls to violence. However when you start to focus on "hate speech" (which is where this line of reasoning will take you) and add propaganda to your moderation toolkit, then you start to cross the line into full blown dystopia territory.

Again, this may be a more compelling example of how you might define "hate speech". But if you think facebook has a responsibility to start moderating speech based on its perceived "hatefulness", then you're still going to end up at the same destination, where genuine public discourse is gradually replaced with corporate approved discourse.