Specifically, as a guy, I found some of the marketing material distributed at the event pretty offputting. Most of the stuff was color-coded, either pink or blue, and that was the first weird thing. Why would you reinforce the traditional gender roles like this if you are truly trying to change them?
Second, I didn't keep the materials, but as I recall there was one that was making the suggestion that "every fairy tale starts this way." Well, maybe, but that suggestion is not really welcome in a professional setting. I wonder if that's the right approach to encourage guys to start taking women seriously in the work setting.
Bottomline, the motivation of the event is commendable, and I am all for adding more women to the technology sector, but adding sex into the promotion of a hackathon, and so badly, will not get us there.