However, that is not the impression that I got from Brook's quotes. The word "perfect" has one meaning, it is not a relative thing. If you don't actually mean "perfect" then use another word.
I still see a strain of absolutism showing through when you say "the "perfect protagonists" are the ones who always live life according to moral values without ever slipping"... Where do these moral values come from? Who agreed that they are the values worthy of being adhered to? And they live life true to these values "Without ever slipping"? Sounds like we're looking at the dictionary definition of "perfect" again... If there's one place where this kind of perfection could be achieved, I guess it would have to be in a fictional book.
Rand says in her works that moral values must come entirely from logic and reasoning, and that that's why her philosophy can be held as a moral absolute: because if it ISN'T logical, she encourages you to disagree with her. It's why people who agree with her seem to do so fanatically: because they're convinced by logic and nothing else that they are right.
And Rand admits from the start that her works portray ideals and nothing more. In her line of thinking if she portrayed only characters with flaws it would make her books subjective and less reliable as a philosophical guide. Nonetheless, there are people who try to live by her words, and many people who have succeeded immensely because of them.
You started out asking me what possible downside there could be to a person believing they are capable of perfection. After I answered, you took the fallback position that perfection isn't actually perfection. You seem a bit all over the place justifying your argument.
Sorry I'm just not buying it. And I'm sure if you were going to buy my argument, you would have done so by now. so I think we will have to just agree to disagree.