The alternative communities often speak for themselves, while the popularity of the mainstream does as well. For a perfect example, look no further than here at Hacker News. The moderation is very active, but here we are enjoying civil conversation
because of that moderation. To go back to my previous example, look at Voat, it’s just the worst place to be. I don’t love Reddit, but it has its upsides, such as science, history, tech, and other subs. Voat has fulminating hate boners and tumbleweeds, and literally nothing else.
So again, we can talk about what we think people want, their declared preferences and ideologies, or we can just look at what they do. The revealed preferences of a significant majority is to be free of trolls and shit stirrers, unless they’re trying to troll or stir shit themselves, then suddenly they’re 1st amendment activists.