I think it's part of the lie of feminism. The feminist movement should be about women having choices -- not about seeing how closely women can act like men.
Sexually, men are wired a specific way. It's not a "get out of jail free" card for bad behavior, but our wiring drives us far more than many of us are willing to admit. Women trying to emulate that behavior because it's "empowering" or somehow makes them "equals" is a mistake. We should be celebrating the differences between men and women but unfortunately we live in a society where its considered "progressive" to deny them instead.
/rant off