While I think it would be refreshing to clear some of the incessant whines out of the forums, I think it would be a bad idea overall.
I think if you created a forum specifically for grievances, it would seem to encourage it. I think the admins and mods are busy as is with the topics they have to police. Even when I post what I feel is fairly innocuous stuff I occasionally get 'ruled'. I'm not griefing that, mind you, just using myself as an example. No sweat, I don't make the rules and conversely don't go out of my way to break them, I just roll with it and post up what's on my mind.
Now that's me just posting up in a comedic light and very rarely with any malice to the posters. Imagine an entire forum of angry numbers guys, grade school dropouts, mouth-breathers and noobs in a contest of sweetheartbaggery with the intellectual vulchers shooting fish in a barrel.