The question of 'why' is an important one, indeed. For example, I suspect that the disparity in cooking and ceramics is not due to a [perceived] unwelcoming culture, or a [perceived] pervasive attitude that men who are entering the field are inferior by default. It might be that women are considered inferior in blacksmithing; I'm not a blacksmith, though, so I don't know. I do know one woman who is a blacksmith, however, and from what I've heard from her--women involved in such a hobby tend to be well received.

People who work professionally in STEM fields in the US tend to be straight white males. This is okay, so long as the reason for the disparity is not that the culture in these fields tends to disparage members of the community who don't fit this profile. If we agree that women and men are roughly equally qualified when it comes to development, then the disparity in terms of participation is worth being investigated. This sort of statement (1:1 ratio) implies equality which will hopefully resonate with the community and ultimately tend towards a zeitgeist wherein people--regardless of gender or any other irrelevant criteria--are welcomed based on their merit.