I think people who hate men or women

Because of their past shouldn't be dating them. In my experience they end up taking it out on you in one way or another. You should address those issues in therapy first, because that other person isn't your idea of "men" or "women", they're a person who doesn't deserve that.

It's sad that we tend to pass our hurt along, but that's why we need to work on ourselves first if that is the case.