I think I must be coming at this gender thing from a different angle.
For me gender is a hierarchy and it is the hierarchy that I want to get rid off. There are also some of the things on the hierarchy that I want rid of but if those things were no longer on a hierarchy they would be meaningless or considered inhumane/unjust and they would die out.
I bet that was as clear as mud! I'll try and give an example.
In my feminism, men and women are not the same. How similar or different we actually are is an unknown because we are all socialized and this skews things enormously. Perhaps the differences are only really reproductive. Perhaps not.
What we do know is that this reproductive difference (which patently does exist) has been taken to divide all humanity into two groups. And one group has higher status, more power and more privilege than the other. And this group seeks ways to control, dominate and exploit the other group.
One of the tools to achieve this is status and that status is where you are placed on the gender hierarchy - the actual gender criteria itself is often irrelevant. What is important is that if girls and women do it, it is low status and if boys and men do it it is high status.
So when a woman argues her point she is aggressive, when a man does it, he is assertive. When a woman has casual sex, she is a slut, a man is a player or a stud, etc, etc. This to me is gender.
I'm having trouble articulating this well. What I mean is the "criteria" in this Dworkin quote. For me gender is the arbitrariness of the criteria.
The essence of oppression is that one is defined from the outside by those who define themselves as superior by criteria of their own choice.
And that is what I want rid off when I say I want rid of gender.