I still believe that on a certain level these men think THEY are worthless. They don't like themselves because, like you said, they never grew out of that headspace of disliking themselves as teenagers.

If a woman likes them, she can only be faking it or pretending to like him, for what he can give her, after all, he knows he is unworthy of actual love, and can only have contempt for a woman who has lowered herself to like him.