In my experience every English-language online forum not rooted in some project or community external to the forum (e.g. an open source project's forum or a local club's forum) devolves into anger, cynicism, and American political partisanship. I suspect that the people who like discussing these feelings are more numerous than the spaces that want to discuss them and so any open forum fills up with their posts. Lobste.rs's unique rules and moderation culture results in a particular manifestation of symptoms but the disease is the same.