Reddit already moderates discussions quite often, and the conversations there don't often reach the level of those here at HN, but still I wonder if maybe too much is too much when it comes to moderation.
I could say something totally offensive and uncalled for on HN, so long as I back it up with why it needs to be said. In other words, I'd argue that the narrative isn't all that matters when it comes to discourse.
Somewhat offtopic, when I look at their material and theming, I think about whether or not I think I'd find people there worth talking to, and that answer is no. ycombinator's landing page, or hell, even Reddit's front page, looks leagues more professional than the weird children's book graphics of Imzy.
I just don't understand what's to be gained in the utilitarian sense by telling people what they can and cannot contribute to a discussion. I really like the idea of just throwing it all out there and then gathering up and working on whatever sticks. Maybe that's why Reddit is semi-appealing.