I find hn a really to be a really good combination of intelligent, grown up discussion with little name-calling etc.
That said, I think on hn one must be prepared to be corrected, -that's just part of being scientifically minded. As the old saying goes: "Iron sharpens iron, and one man sharpens another."
Who cares about my stupid comments, sure, I'm an idiot- I'll agree to that. Unfortunately, I see it happen all the time. The parent of this, for example, was downvoted immediately.
Everyone in this community is prepared to be corrected- the problem is when there's no correction offered. It's a community of suppression, and it's not hard to see.
Perhaps HN users need to be reminded to upvote things that have been unfairly downvoted? (Although I've seen plenty of examples of corrective upvotes supplied pretty quickly).
I don't think it is a big problem though only that it has been slightly increasing.
(one comment you'd see back in the days when comment scores where displayed was: "sorry for the downvote, -reading hn from a mobile device ". You don't see this comment anymore but I'm not sure if that is because it was easier to detect accidental downvotes back then or because people where more polite.)