Britain has 51% women. Women are underrepresented in the Ruby community, but there is no reason why it should stay like that. Is not anyone's job to increase the percentage of female coders. It is everyone's.
To my knowledge, it has never been established that women and men share identical dispositions towards all things. In fact, to me it seems unlikely that it should be so.
Given this, I'm not sure how you can claim that it's everybody's responsibility to push for more female coders. How would we know what the 'natural' split should be?