I disagree.

A man who sleeps with lots of women is doing something very difficult—social calibration, providing value to women, etc. Hence he's not called a 'slut'. A woman who sleeps with lots of men isn't doing anything great. All men want to sleep with women. A woman just decides to lower her standards. It's her right to do it, but experience has shown us that women who sleep easily with a man usually is left unsatisfied with her relationships as life progresses. 'Slut' is the word used for such a person.

In the same way, 'narcissism' is used for a wrong type of thinking about self-worth, and the comments similar to /u/moonlightttt gave a more apt description.