It's a non-optional social convention.

There are degrees of non-autonomy. Dependency is at the extreme end. Vulnerability is also on that scale. Many groups in society are vulnerable due to prejudice, ignorance, oppression and domination by more powerful groups. Women are vulnerable in this way. To be clear, it’s not that women are incapable of achieving autonomy, of course they are; it’s that the social conditions of sexist societies constrain their autonomy. The constraints on women’s autonomy are external, not internal, and it is these external conditions that generate women’s vulnerability. […]

The Occupy movement needs a serious injection of feminist politics. This doesn’t mean having a token female facilitator at meetings or patting one’s self on the back for listening to a woman speak until she has finished; it means recognising that women have different needs that need to be met and finding practical and viable ways of meeting those needs. The fact that there has been scant discussion of these rapes and what to do about it highlights the fact that, even among activists, violence against women is not taken as seriously as it should be. The Occupy movement needs to wake up to this problem and do something about it. […]

To anticipate some criticisms, let me clarify a few points. Firstly, I’m not saying inclusion is the be-all and end-all of all protest movements. I’m saying that for a movement that claims to speak on behalf of the 99% it is crucial. If the Occupy movement is claiming to speak for the 99%, they need to recognise the multifarious needs of different types of people, and to cater for them. It’s no good saying “We are the 99%” but we exclude disabled people. Or “We are the 99%” but if you’re a woman you’re responsible for your own safety. We might be “the 99%” economically (and even that is a dubious claim), but we are not all white, male, heterosexual, able-bodied men; most of us aren’t and we need our differing needs met if we are going to camp outside together.

Maeve McKeown’s article on OpenDemocracy, relevant on a much wider scale than just the Occupy movement