I've addressed this topic before, but maybe it's time for an actual research paper on it.  I'll think about it and see what kind of research I can actually dig up.

In the meantime, my general thoughts on the matter:

Religion hits women harder than men on the sexual morality front.  There are several reasons for this.  The first is purely biological.  Women are "designed" to be much more sexually choosy than men.  All things being equal (in the feminist sense) fewer women will engage in frequent casual sex than men.  Also, women are designed to be receptive to intellectual stimuli much more than men.  In other words, in a default state, women don't often get horny from looking at a guy.  They get horny from hearing him talk or watching him demonstrate prowess at something or other.  As you're well aware, it just takes a naked picture of a woman for most guys to get at least a little aroused.  Finally, women are geared farther towards emotional sexuality than men.  That is, most women desire emotional intimacy as much or more than sexual intimacy until they are turned on.  As any guy knows, you have to warm most women up to physical intimacy, or they're going to be perfectly happy sitting at a coffee shop talking about their feelings... for hours.

When Christianity preaches its message of sexual purity, restraint, and propriety, it taps into the normal biological sex drive of women far more than that of men.  Since women are already geared towards choosiness, reluctance, and nonsexual intimacy (relative to men... I know women get horny... I'm talking about relative measures!) they are easily indoctrinated into a system that exaggerates their normal drives to the point of absurdity.  Men, on the other hand, tend to ignore a lot of the sexual mandates, particularly when they are not being watched by nosy church women.  After all, men are not geared to be easily indoctrinated into chastity, reluctance, and choosiness.

The second reason women are less likely to "come out" about liberal sexual values is that even outside of religion, there is a really nasty competitive streak among women, and it's usually a pretty bad idea to give them more ammunition.  That is to say, women are far more likely to call other women sluts than men.  It's pretty obvious if you think about it.  Men want every woman except their own to be sexually promiscuous.  That way, they get to father a child with relative certainty and have affairs on the side.  Women, on the other hand, want other women to be as sexually chaste as possible because that reduces the competition for their man.

To restate this concept, it is in a man's interest to cloister one woman as completely as possible to ensure parentage.  After all, a man can never be completely sure he's the father, but a woman always knows she's the mother.  Even so, there is no harm whatsoever in a man having sex with as many women as possible, so long as he's able to keep the one woman (or two, or three, if it's a polygamous society).  To this end, men want most women to be sexually promiscuous, increasing their chances of easy sex.  Men's interest in women (biologically) is basically short... however long it takes to copulate.

Women, on the other hand, have a long term interest in a man.  Any old man will do for the copulation, but for the pregnancy and childrearing, a man with an emotional commitment to both mother and child is the best case scenario.  For this reason, women have every reason to reduce the competition as much as possible.  Consider that historically, all a man has had to do is lock the door when he leaves the house, and his woman is safe from the competition.  For a woman, it's much tougher, since the competition is out there where the man works.  This state of affairs probably extends back to near the beginning of humanity, since men have probably always been the ones to go out hunting, raiding, raping, and pillaging, and women have probably always stayed in relatively protected areas.  So, for a woman to reduce the competition, she must discover something more indirect, like.... for instance... sullying the reputation of the women around her...

See how it works?  Women are programmed to try to reduce other women's sexual appeal.  Since they're trying to sell themselves to their man as loyal and devoted, it makes sense that they would paint other women as promiscuous, slutty, and skanky.  Thus, there is a biological explanation for the social behavior of repressing sexuality through cultural standards.

A woman need not be consciously aware of all this evolutionary psychobabble.  If she feels emotionally reluctant to buck the system, she's probably not going to buck the system.  Add to this the fact that bucking the system sexually is not nearly as important to a woman as it is to a man, and you've got a recipe for exactly the situation we see now.  Remember, women are programmed for more subtle sexual stimulation than men, and are not as drawn to the blatant visual sexuality as much as men.  They prefer romance novels to porno mags.  It's simply not that important to most women to have the social freedom to have sex with a different man every night or to go to a strip club.  Frankly, most women have bigger fish to fry, and would be more emotionally supported if they tackle other issues like job equality or going after deadbeat dads.

So, in summary:

1) Women are more susceptible to religious sexual morality than men.

2) Women are less biologically inclined to act like men sexually.

3) Women have a vested interest in promoting sexual restraint among other women.

4) Women generally have bigger fish to fry than liberating themselves in the way you're talking about.

Finally, consider that you as a man have more interest in women sexually liberating themselves than women do.  The more sexually liberated women there are, the easier it's going to be for men to get laid when they want.  In general, any woman can get laid whenever she wants already, so there's not that much added benefit to being really open about it.

Isn't it just a case they while all women and all men generally want the same legal rights that there isnt a consensus beyond that.

There isnt a voting group 'women' or a voting group 'men' in the same way there isnt a voting group 'atheist'

All are valid points. As I have stated before, I am in complete agreement with sociobiologic explanations of human behavior. Yet the evidence ways heavily against any biologic essentialist notion of herd mentality among women. Also it is in our hardwired nature to place the needs of the self and one's family over and above the needs of the masses. Yes, we are indeed selfish by nature. Men and women want their personal freedoms to come first before anything else. We are all libertarians which is why in the long run collectivist ideologies have limited success. In contrast to libertarian feminism, often mainstream feminism like orthodox religions expects conformity to a rigid cultural ideals ie. women should not engage in the free market, women should not become sex workers even if those professions are freely chosen. Not all women want to become CEOs, neurosurgeons or tenured professors working at the NIH. Some want to be stay at home moms raising children. Yet this would be an affront to mainstream feminism's goal for equality. Although there are a variety of feminisms, they can all be distilled to those who are libertarian and those who are collectivist. And these ideologic differences (the latter being more mainstream) are due to the fact that many women don't want the state to interfere in their lives. I so no biologic basis for women choosing a specific ideological stance. A lesson should be learned from male homosexuals who want greater inclusiveness in society but are highly resistant to any intrusion by the state.

I think it's great that you are willing to take a look at what feminism is as men are a part of the lives of women and we need support from men in the quest for a more equal society.  I would suggest that you spend some more time looking into feminism before making judgments regarding the movement as a whole.  The mainstream media has much fun painting the movement as stuck in the 70's.  After all, if the movement has grown and changed as the lives of women have changed then it may have to be taken seriously and the patriarchy may have to give even more ground.  Better to portray feminists as bitchy, old women stuck in the past who want mind control over all other women.  This is not an accurate portrayal of feminism, but rather of a divide and conquer strategy that has been rather effective.

There is an old guard in feminism that does not automatically look to my concerns.  Given their life experience, that is to be expected.  That doesn't mean they don't know how to listen though.  I saw a huge shift in the 90's as more women came of age that did not see children and/or marriage as the prison sentence it had been for many of the old guard.  There was definitely some resistance to this point of view at first as feminist activists were used to having to fight hard for small gains and always be on the defensive.  That resistance has greatly dissipated.  It is understood that child and elder care, division of work in maintaining the home, and other "domestic" issues do have a great impact on the lives of women and need to be addressed.

I appreciate the reminder of what a sexually repressed, divorceless, marriage only based culture cost women of previous generations as we do not need to be returning to that model.  I very much appreciate the willingness of childless, elder women to fight for my needs in caring for my family.  The inclusion of expectations for men in the home and fighting for government support for child and elder care are wonderful changes that society needs.  At the same time, they still fight against state intrusion into my body.  What more could I ask for?