Well, let's remember that the Slayerettes cutting their hands over the hellmouth seal was supposed to be something 'deep' about menstruation.

Only a guy could think that crap up and think it's a teh wonderful hommage. It's sort of like those ridiculous 'Happy Period' commercials. Only a guy could think that up too.

Women actually have to deal with it on a practical level and... it makes a difference.