I think the conversations should be happening regardless of the site. If I receive a comment on H/N, I want to reply in the easiest way possible FOR ME so we can carry on the conversation. Right now, I have H/N hooked into Engag.io, so I can follow all discussions in one place. That's easy.
Too many places to moderate comments is too difficult. This difficulty only increases as your stories are published more broadly.
From a site / comment manager perspective, is it quality or quantity that drives the decision to keep comments open / closed?
I look at it like an actor - when you are starting out, you'll take all the publicity you can get. When you're on top, you've accomplished being noticed, now you want "better" publicity.
Or, something like that.