> to me the difference is plain to see.

Agreed. HN isn't 100/0 signal/noise or even 100/0 politeness/rudeness, but I get the feeling most people discuss things with a relatively open mind here, and it's not uncommon for people to either be corrected by others and accepting it, or correcting themselves if they've found something out after submitting their comment. Just seeing that happening makes me hopeful overall.

It's a huge contrast from basically any mainstream social media, where the only time you'd see something like that is when you're talking with literal friends.