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.
Not OP, but it's not smart/educated that I like to have these conversations with. It's humble, polite, open minded people. For the most part these two axes are usually orthogonal and independent. The one correlation I've found is that if one's lack of education is approached in a way that contributes to them feeling insecure, then they move into survival mode, become defensive, and thus less open minded.
HN tends to attract people from an educational/professional background that encourages critical thinking. Even if the user has a degree in the liberal arts, the application of their mind in technology forces their thoughts in a way that pushes them to think critically and not just accept what is given to them without question - I would think. As with all thoughts and theories, this is a general rule and a hypothesis, I might be way off the mark.
Generally speaking, though, people who have learned critical thinking skills seem more willing to discuss an issue in a reasonable manner and drill down to the truth of it, rather than "dig in" and just decide they're right with whatever information they might have on hand.
I only bring this up as I have a fine arts degree, but shifted into programming as I wrote scripts for different art applications and the transition was natural as I had a background as a script kiddie from my high school days. A large amount of the people I went to school with, however, are absolutely unwilling to apply critical thought to specific subjects even though some have masters degrees.