But does this place have to be StackOverflow? I think it has space for discussion in comments, chat rooms, etc., but the main artifact is intended to be an easily searchable Q&A archive.

I think they need to work on communicating that much more clearly, but ultimately they don't want to (primarily) be a place of extended discussion, debate, and so on, and I'm not sure it's fair to say "no, they're wrong" to that.