In order to address enth's question ("Why haven't women become revolutionary if they're oppressed?"), I first had to ask "Who would women be rebelling against?" Well, men. Even disregarding emotion completely, there is a major problem with a revolution of that nature. Specifically, women and men cannot exist entirely independently of one another. At least, not for more than, say, 70 years.
Unlike other rebellions, where the revolutionaries could (at least theoretically) exist entirely without the involvement of their 'oppressors', women and men are dependent on one another for their very existences. Neither side can afford the equivalent of a bloody coup d'etat that would annihilate or alienate the other half of the human race. (There are also complicating factors such as unequal oppression of women, women who do not feel oppressed, affection and love between the sexes, etc. but those are topics for another node.)
In conclusion, I would hypothesize that a fundamental codependence could explain the relatively slow nature of change in the relationship between the sexes. For all our differences, and the inequalities that do exist in human society worldwide, women and men need each other.