Because I think there are people, particularly MRAs that are realising that the only time politicians ever really think about reversing gender discriminating laws like this is if women are suddenly the victims of it as well. So it's partly a case of if they're going down they're going to take feminists with them as well who are the main ones that are opposing having conscription for women.
Also yes, it's only ever been men who have had to sign up for the draft in America, no idea why the democrats would push so hard for it though.
Weird, right? Although I've never met a Democrat who didn't think everyone belonged to the state; they just seem to believe the state is always a force for good.