> far too many people would rather down vote than refute an argument
Another challenge is that there's not always a consensus about what downvoting is appropriate for. (Disagreement, tone, bad faith, personal attacks, poor logic, off-topic, etc.? Or just "too controversial and not likely to lead to a good discussion, even though it might well be correct"? For that matter, people can't quite agree on what is or isn't on-topic here.)
I sometimes wish HN had downvote reason metadata so that people could understand more about what was prompting other people to downvote them. You can see that people are often genuinely confused about it, but the site rules discourage people from complaining about it, and it's hard to distinguish a confused question from a complaining question when people ask why they were downvoted. But we don't really have any challenge for people to say "I was offended by your view" vs. "I think you treated someone else in the conversation disrespectfully" vs. "I don't think HN is the right place for this argument", etc.