One thing I noticed early on here - I don't think I'd found you yet, even - is that authors who consistently reward quality comments with upvotes have much better-quality comment sections than those who don't.
Obviously this is a large minnow/dolphin privilege, but as we get more posters into those groups (partly by upvoting their comments) I think the overall quality of comments on the platform should improve. That may already be part of what you're seeing.