For me, the public-ness is what makes it compelling. IMO what it lacks is an HN/reddit-style downvote, that would immediately send the vile comments to oblivion

For me, the public-ness is what makes it compelling. IMO what it lacks is an HN/reddit-style downvote, that would immediately send the vile comments to oblivion. Then perhaps you could choose to only let users with positive karma reply etc. HN & Reddit does have some rude/know-it-all comments but I don't see much of the real nasty stuff.