They're not just needed, they're _massively_ successful. While I have some small issue with some of the branding, it gets people to show up.

I know someone who tried to get a 'new people programming' event started for six months, never got more than 4 or 5 people, and they were all men, even though he was trying to be woman-friendly. He then changed to make it a RailsGirls event, and he had 300 people apply for the 15 seats he was budgeting for...