Maybe. But I think that it's, precisely, because we are random strangers in the Internet and we all know how easy is to misunderstand intentions by text, that we should think two times before downvoting.

It's my personal opinion that downvoting is used too easily in HN.

Sometimes it seems that we are trying to filter opinions that we don't agree with, instead of policing good manners and filter irrelevant to the subject comments.