What is wrong with feeling hate? What is wrong with expressing it? There's some good evidence that it's the suppression/denial/dissociation of our "hate" feelings and redirecting them towards ourself in early childhood that causes a lot of emotional difficulties later. I think that having those feelings come up in therapy -- and having a T that can understand that -- could be a good step for lots of us, to help us learn about and accept the fact that our capacity and ability to feel hate is not in itself evil, but part of the emotional equipment we were born with.