More and more, you're reading (or, at least, I'm reading) that when women take charge of their sexuality (e.g., The Vagina Monologues, or sexually assertive teenage girls who may or may not be having sex but in any case are making up their own minds on the matter) it is disempowering to women.
Why is this? Is it a case of the cultural right aping their
betters opposite number? Well, yes, but there's more to it than that.
To take this viewpoint, it seems to me, you have to be anti-sex.
If sex is dirty (or involves the body at the expense of the soul, or spreads germs like any other form of bodily contact, or what have you), it follows that encouraging women to do it on their own terms doesn't lift women up, it simply encourages them to embrace filth. If anything, it makes it worse, because rather than simply being passive victims of the lust of loutish men, women are being urged to own their dirty, dirty sexuality.
Alternatively, this would be the view of someone who values women only for their sexual "purity". Encouraging women to up and have sex, then, makes them less pure, thus less valuable.
Or you can assume that women don't really like sex. So saying women should embrace sexuality is to say women should become more like men -- thus promoting men as the standard -- or to say women should be alacritous about making men happy. Female sexuality, in this view, is inherently subordinate to male sexuality, if it exists at all, so saying "women should be more sexual" is equivalent to saying "women should sexually gratify men." If women are incapable of sexual agency, women's sexuality means having sex with men for the benefit of those men.
Ultimately, though, this line of reasoning is itself disempowering to women: It takes for granted that women are different from people. People have wants and needs, including sexual wants and needs. Women, being people, are included in this. If for whatever reason someone decides that women don't have sexual wants and needs, that female sexuality is defined in terms of male sexuality1, that person is, at least in a small way, denying women personhood.
1This is no more true than the other way around. Well, it shouldn't be. Too often men approach sex with the mindset "what will get me off" and women approach it with the mindset "what will get him off" and while it's good to work towards a common goal, that's probably not the best realization of that.