Any comments section would require moderation, and internet moderation is a huge pain in the butt. It's not an unsolvable problem, as the examples you give demo

Any comments section would require moderation, and internet moderation is a huge pain in the butt. It's not an unsolvable problem, as the examples you give demonstrate, but it does require a lot of effort, and I think you'd be pretty hard-pressed to find academics willing to expend that effort.