hmmm........well nearly all mechanical hobby sites are dominated by men as far as I can see, and as this is true in virtually all cultural settings I suspect it's roots are in anthropology. Division of labour on a sexual basis would appear to be a characteristic of surviving human groups. I observe that most women are more interested in ribbing or whatever when there is a chance to meet friends or new people and interact socially. Social anthropologists say there are sound survival reasons for women to do this; as there are for men to compete for status, and technological advantage.
That said, in a civil and free society, it is unfair to assume a man or woman will act as the majority do, and deny them their chance to express themselves and fulfil their potential; for instance ellen macarthur. I suspect if you offer a safe, clean, social fun experience, women will be more likely to take part, MOST women. My wife won't go near the rib!