This doesn’t appear to cover the other kind of comment-moderation problem: that where overmoderation and attachment to poster identity leads to an environment of stifling conventionalism.
Photography communities in particular (e.g. flickr, instagram, 500px) are vulnerable to turning into circlejerks where no-one is willing to say what they mean for fear of appearing the negative nancy (no pun intended) and where high post-count contributors’ poorly-supported opinions become elevated above said views’ merits. In such communities the typical discussion is at the level of tepid platitude: “good exposure!”, “nice depth of field!”, or “cool HDR!”. On the other end of the scale there’s the imageboard style of community where anonymity is the norm, feedback is uncompromisingly harsh, and uselessly opaque criticism appears such on its face; unsuited to the overly sensitive but hideously valuable to the advancing novice.
Ordinary web forums, with tools oriented towards a punitive “he said the n-word! delete his account and everything he’s posted! persona non grata, in damnatio memoriae!” school of moderation, strongly tend to the former.