it frustrates me too. its so so so horrible. actually women ARE allowed in the masjids in my area. thats non muslim women coming to visit are allowed. just not muslim women to worship. dont ask me why.
"If one of your women seek permission to go to the Mosque, then do not forbid her" [bukhari & muslim & nisaai]
so so women are allowed to go to the mosque because RasoolAllah (sal Allah hu aley hi wasallam) has said so, as it says in surah al ahzab v 36
"It is not for a believer, man or woman, when Allâh and His Messenger have decreed a matter that they should have any option in their decision. And whoever disobeys Allâh and His Messenger, he has indeed strayed in a plain error"