Main problem with promiscuity is not the n-count itself, but that it exposes the woman and the man to the danger of becoming distrustful of future relationships, jaded, and "throwing sex out of their system." And yes, many promiscuous women are in this danger, especially if they did not become promiscuous entirely on their own, but rather as a reaction to their mental trauma,etc.

The fear of many men is caused precisely by this, by the fact that a woman who has been dissolute in the past will always have “one foot out the door,” which will really make such a man unsure of himself for objective reasons.

You really can't find a man or woman who will seriously say: "Gods I'm so worried about my partner's past lovers while my partner treats me with passion, understanding, genuine love and he/she fucks me like there's no tomorrow."