This problem is easy to solve. Downvote bad comments and bring in active moderators whose job is to message users that show a pattern of writing bad comments a

This problem is easy to solve. Downvote bad comments and bring in active moderators whose job is to message users that show a pattern of writing bad comments and help them do better. If the user doesn't improve over time, ban. There must be a hundred competent people who would be willing to assume this position.