The "you didn't model it yourself so it's not art" people have galleries, so requiring people to have galleries to comment wouldn't keep them out. Plus, the trolls already sign up in order to troll. They'd probably just steal other people's art if having a gallery were required. Heck, it could become an all-new way to troll. I really think moderation is the only solution. Or at least, giving artists the choice. We already have the choice of allowing comments or not. Why not allow us to moderate the comments or not? Like the merchants do. A simple approve or disapprove, no editing of comments or anything.