Rob, your comments are well-taken and very true. I agree that constructive criticism done in a respectful way does more good than harm. I post regularly on a certain blog that will remain nameless, but it's known for harsh, hateful comments from posters and is very popular. There's a few posters who say the nastiest things about the models' appearance. I tend to ignore those, altho sometimes they're funny. But what's not funny is the fact that it takes a lot of guts to put yourself out there, and for that, I have the utmost respect for those in front of the camera. On the other hand, for those who subscribe to these sites and pay their hard-earned money, emotions can be strong when they feel they're not getting their money's worth. So I think that is another aspect of such behavior. Another complaint I hear often is when a model appears too often, which is not the model's fault.
But I certainly agree with your sentiment, and I try very hard to be respectful and consider the model's feelings. Most of the time my dissatisfaction is more toward the producers and directors than the model.