I agree with this. I suspect that any community with “downvoting” or similar would skew more forward outliers, because the prevailing group-think will downvote contrary content and getting downvoted stings, scaring off many who might otherwise add diverse perspectives.
But even without voting mechanisms, nasty replies are just as bad or worse, so the general trend of chasing off the people who see things a little differently seems pretty universal to me.
I walked around the problem of replies(on Reddit/HN) by never looking at them. I have a red envelope of 150 or so now.
Every once in a while I imagine something anxiety inducing about them, or catch a glimpse(and more often than not a positive one) in the automatic reply emails Reddit likes to send me. Sometimes I will look back at the thread, if I really want to know.
But I don't use these platforms to converse, even though I will happily make a reply to an existing thread. They are both too fast and too slow to be conversational. I use comment threads as a writing prompt instead, and by ignoring external feedback I don't experience pain from them, even though some of the time this might result in someone asking me something and never hearing a reply. If my idea is good, someone copies it and I see it in a later thread.
But even without voting mechanisms, nasty replies are just as bad or worse, so the general trend of chasing off the people who see things a little differently seems pretty universal to me.