Personally, I don't care if I'm downvoted. Given that I don't usually say incredibly stupid things here, when I'm downvoted it is almost always a temporary phenomenon (most often it seems like fanboy kneejerk downvoting because I said that whatever company/product they love might not be perfect) that eventually corrects itself, so asking about it wouldn't really serve any purpose.

I have to admit that when people do say incredibly stupid things (and not just things I disagree with, but really stupid/unhelpful comments), I love it when they complain about the downvoting in a subsequent post because then I can downvote them twice. I'm not sure if that is proper HN etiquette or not, but I'm guilty of it.