What we're talking about here isn't art theory though, it's specific criticism on specific pieces. I would find it astonishing, not to mention rather disappointing, if the people running an art site couldn't see the difference between the two. IRL, artists meet in all kinds of places to talk about theory (general) and critique (particular). It seems odd that we can't easily do that here. A crit forum would address that - make r'osity even more like what artists do when they get together and create their own groups. There's a concern that's been expressed before about how a crit forum would invite trolling. To that I'd say look at the difference between C&D and OT. To a large extent, OT is restrained and mature in discussion. Where things start to get out of hand, it's often the contributors who step in to calm things, before the mods need to.