Some women do not masturbate for pleasure; they masturbate to make a political statement: to remind us that women do not really need men (or at least not as much and as frequently as every single male chauvinist and every single misogynist believes).
It was masturbation, not willpower, that made it possible for gazillions of women to walk down the aisle with their reputation and their hymen still intact.
Some women have been faking orgasms for so long that they sometimes fake one when they are masturbating.