Firstly, online communities are usually less comparable to all of your IRL social surroundings, and more comparable to special-interest conferences, festivals,

Firstly, online communities are usually less comparable to all of your IRL social surroundings, and more comparable to special-interest conferences, festivals, or other places where many somewhat more like-minded people with a shared context meet. There's definitely a lot of self-selection going on here. Secondly, I believe there's a flipside to many of the things that can go wrong when interacting online. Maybe if you read something without knowing the other person, and without having a ten-year history with them, and you can re-read and take time to ponder your answer, it also allows you to be more thoughtful and not let all the baggage people have with each other in the way?