I would say negativity bias feeds heavily into this one. It's easy to overlook a lot of the fairly civil discussion if there is just 1 or a couple of people being unrestrained with their comments.

That being said, the issue is a combination of relaxed moderation, and generally they aren't quick to act on feedback, and when you do so to the extent seen on this game (bar a few exceptions), then you just replace what would otherwise be a civil discussion with something more akin to exhaustion and annoyance, this tends to happen with people that don't feel like their concerns are heard.