Some people want constructive interactions, some want lulz and flame wars. Many people want both at different stages in their lives, or even simultaneously on different forums. Just remember you are free not to read and free not to reply. Wish there were AI personal moderators to selectively ignore stuff.
AI moderators don't have to be personal. It would be enough to tag comments as constructive, lulz and flame and let users decide which type they want, or to which degree they want it. The technology of spam-detecting Markov chains should be enough since the users can easily correct the classification.
Since the feature is possible but not used, question remains why users don't need it.
If I were AI, I would remove any post not containing a link or a number. And remove any comment containing a sequence {capital I followed by a space}. Including this one :)
