The OP uses the word "insane", not outlier. It's clickbaity, and used in jest, but I think it better captures a subtlety of this phenomenon: The prolific commenters are molding every discussion in their image. They might have an interesting angle on the story, or they might just be saying trivial things with beautiful prose. In any case, there is a lack of diversity in general -- discussions are driven by the worldview of a few.
That would be an argument for lurkers to make an effort, even if, like this comment, it's just a barely-formed idea.
Edit: "molding the discussion" -> "molding every discussion"
This is actually why disinformation works so well. Many people are consumers. A handful of people create content. Everyone has an expected behavior in a rather fragile system. If an organized group comes in and acts in a way that is outside of the system norms, they can very much control the dialog.
I did a project on this during my Masters. [1] Reddit has an option to display your upvotes and downvotes publicly. About 2% of users have this option enabled. I scraped a random sample that I found from the torrent of all Reddit posts and comments. I looked at pairs from that set that shared common votes and the highest pair was from /r/the_donald. This behavior is what allowed it dominate the front page for so long. When most users are just voting on 1 or 2 things per page, and someone else comes along and votes for every post they see, it can greatly affect what is displayed.
When you have a small set of people controlling a conversation, they can manipulate what a huge number of people consume. Social media is an incredibly effective propaganda machine!
1. https://www.reddit.com/r/dataisbeautiful/comments/82ylpv/_/d...