I'm afraid I think the 'informal patriarchal conspiracy' is at work here. When Cosmo launched it carried a male centrefold - the first one was Burt Reynolds iirc! The centrefold was dropped due to pressure from advertisers and distributors, not the reader, who enjoyed them. For Women suffered a significant amount of blocking activity, despite a healthy balance sheet. A collective of film-makers - I've forgotten the details - failed to raise sufficient backing for their woman-centred, soft-focus projects despite having plenty of big-name support. Business, it seems, likes women to be sexy but not to have sexy feelings of their own.
There is another aspect to this, though. If you remember the study that was done (last year?) on visual arousal, you'll recall the disparity between the female subjects' physical responses and their 'felt' reactions. The women became physically aroused at a far wider selection of visual triggers than the men did. However, they said they'd felt nothing. We are so out of touch with our own sexuality, we don't even know when our bodies are aroused. Kinsey remarked on the same phenomenon, as I'm sure other studies have. This can only be due to massive social conditioning - which, in itself, would prevent the majority of women from acknowledging a sexual response to the stimuli. For that reason, the "women's porn" market has limited potential.
Generations of women, however, have been made very happy by Mills & Boon, Black Lace & their stablemates. There's a reason why historical TV dramas keep getting made, and it's got more to do with repressed lust than historical accuracy. My theory is that these actually reflect women's sexuality - the suppression, social navigation and so on - better than straightforward porn. It's an interesting topic. AF, I'm neither a porn fan nor a user but I am very interested in female sexuality and how it is used/abused. I think it's a shame we're not "allowed" to be horny the way men are.