Study after study confirms that women backstab, undermine and put down one another -- at work, in the PTA, out for drinks -- basically taking every chance they can to act out the movie Mean Girls long past high school.
Gender equality is not for women to "overtake" men or actually be men. What's happening is that women are getting more choices and more confidence to make those choices. What's happening is the decline of expectations, long and slow though it may be.
If we say that slut is a bad word, we are implicitly saying it is bad for women to want to have sex. If we say that prostitute is a bad word, we are saying that taking money for sex is an insult. Neither is automatically true.