Blame the system. Rating system was a good idea to encourage community self-moderation, but most people treat upvotes/downvotes as likes/dislikes, even when specifically asked to use them differently. And, because of that, places with rating systems inevitably boil down to circlejerking, infobubbles, and tribalism. Too bad the only alternatives are spamholes, chaotic messes with power-tripping moderators, and AI blackboxes designed to control your mind.