You need to think of this from the point of view of the women. How would you feel if someone put you up as a perk, based only on your gender? I would feel like meat.
Edit: I'm not saying this was intended. Maybe they were actually trying to appeal to women (or men) who didn't want to work in a "bro environment", as pessimizer put it. Lots of explanations but they need an actual apology for messing up so bad.