[ChrisKor]

I am actually not sure I would call Kialo debates, debates, they seem to me more like argument maps, coupled with Wikipedia. Also, they aren't antagonistic and there isn't really a winner.

I have gotten plenty of claims rejected because they were already in the debate.

I think the most important aspect of an ideal platform is that its users are not encouraged to write outrageous statements that then garner the most likes / upvotes, as is often the case on Twitter and Reddit.

At HN I am actually frequently surprised that things stay as civil as they do, though, as you write, they often go round and round and are a bit confusing for readers, which isn't HN's fault but just the nature of threaded commenting forums.