Lessee, because Batgirl and Batwoman are already taken names?
see, this is my problem with the Batman universe. They've already taken up the Batgirl/Batwoman names with OTHER characters, so there's no way they can make a "female Bruce Wayne" character, because if you call that person Batwoman, you are erasing the existence of the actual Batwoman/Batgirl. There can't not be a Batman, because Batwoman relies on Batman existing. Batwoman can't be the "only 'Batman' " because they would never want to do that