At present, 150 of the 270 comments are children of Bakkot's comment, arguing about infanticide. It seems obvious to me that we ought to seriously discourage promoting discussion on ideas in introduction threads, and instead point people to open threads / a primer on writing discussion posts.

Another possible solution is to have new introduction treads on a more regular basis. Say, monthly, like quotes threads, or as they fill up, like MoR threads.