We keep talking about truth. My experience is that truth is elusive, even with people who mean well. My experience is that even in the most community-oriented online groups, not everyone means well. And my experience is that identifying the difference, with the limited tools available in a forum, works out similarly to throwing accused witches into a lake--if they drown, then I guess they weren't witches after all.
Even with the vast construct of the complicated feedback system provided by eBay, which has been used often as an example in this thread, conflict abounds. Nobody sane would volunteer to be an ombudsman--who wants to be in the middle of every argument, usually pleasing nobody and still having no investigative power necessary to learn actual truth?
While I think it undermines community, I would rather have the for-sale forum with no comments allowed except from OPs than not have it at all. And maybe it could be done without increasing the burden on the mods, which I think is a requirement that must be fulfilled.
One final bit of experience: It's quite common for people to volunteer ideas about how other people should do things. I have found myself in leadership roles in a variety of volunteer efforts for some reason I can't fathom, and have heard such advice endlessly. They mean well. But usually the people who are actually doing the work have already debated those topics thoroughly, and advice doesn't really help. I don't think it's pandering to the mods to avoid giving them "free" advice.
Rick "kindergarteners are often better behaved than groups of mission-oriented adults" Denney