It does not come from a place of anger - it is merely passionate. Changing someone's mind takes a long time so obviously that isn't the goal here. However, you can broaden your interlocutor's horizons by exposing them to a different set of opinions. I consider it a stressful albeit enriching experience plus the internet is arguably a safer place to do it than a real-life setting.
There is that and to some extent I agree with your point, but the trouble is it so often becomes personal which then spills over into other areas of the forum in question in the longer term and can become disruptive. It might be better once we've resurrected the general chat forum which is languishing where nobody can find it, but still waiting for the go-ahead with that. It can be a headache to babysit though: there's a reason most forums disallow politics, religion and the usual slew of "don't go there" debates.
