I think that
women's
sexuality is more valuable to women in modern Western society than it was in say,
Victorian/
Gilded Age society, but not particularly because of
porn. Women's sexuality is more valuable to women now because we're aware that being sexual has benefits (pleasure) for us, whereas at that time the prevailing society insisted that sexuality was valuable only as a method of achieving motherhood, and using it for any other purpose was a good way to wind up at best considered "fast", quite likely called "ruined" or "fallen."
The beginnings of the Sexual Revolution (probably early 1960s; Helen Gurley Brown's Sex And The Single Girl came out in 1962) predate the era of porn being chic or even all that big a business (say, when Deep Throat and Behind the Green Door came out in 1972) and probably pornography's wide availability is a direct consequence of the fact that sexual mores were already quite changed from their state fifty years earlier.