Not only does it hurt lgbt liberation, it also boxes men and women into a gender identity before they are even born. Even when a person is completely straight and cis it could hurt them in preventing them from expressing their full identity.

Me as a straight cis dude really struggled with being boxed into masculinity. My parents were awesome though, so I just got scented pink letter paper with cute cartoon mouses when I wanted that as a kid.

I mean yeah I agree with you. They aren't good.