It's an interesting idea for sure, but I'm not sure how or if such a thing can exist. Moderation becomes a headache, and well, a lot of truly brilliant people I've met in life have zero interest in debating it. How do you keep out the YT commenters, Fox News or r/politics commenters, etc?
It would be interesting if HN had some bucket like /offtopic, for things that are flamebaity and removed from the main view, but I fear it would attract the aforementioned people who only ever troll there, and dang probably having zero interest in mod'ing it.
I mean, maybe, although I think there is substantial non-overlap between "people able to have a good-faith, respectful debate" and those traditionally considered "smart and/or well educated".
As a lot of comment responses attest, it seems the answer may just be "it's human nature, it's not possible", but given that I just see these kind of topics more and more and more (i.e. interesting but where the debate ends up getting more vitriolic and going in circles), I'd hope it's something beyond just human nature at work.
Heck, maybe even the possibility to keep interesting upvoted articles without any comments would be worth trying.