You're right that this has unilateral benefits, but it's even better if something like this becomes encoded in social norms. For example, there are online commu

You're right that this has unilateral benefits, but it's even better if something like this becomes encoded in social norms. For example, there are online communities where it's simply expected that you'll assume good faith and basic decency from the people you're arguing with. To do otherwise would be a serious faux pas. There are also online communities where everything immediately devolves into flamewars in which everyone is shouting and no-one is listening, and that is considered normal and inevitable. And then of course there's a whole spectrum in-between. I can tell you from experience: the places with nicer discourse norms are more pleasant and the discussions tend to be much more interesting and productive. (Compare HN with, say, most of Twitter.)