What if there was a type of person that never did anything but try to kill and rape other human beings all the time? What would a society do with such people? Put them in secure hospitals I suppose (not being sarcastic, that's what would happen). But the women don't have secure facilities like that.

(Note - I don't think men really are like that (not does Tiptree) but that's the idea the women have to start with, and the men in the story accidentally confirm the mistaken idea in everything they say and do)