Unfortuantely most girls don't realize that throwing away their sexuality on tomcats means they come to marriage (if they ever marry) a tattered used slut. I am not saying that every woman who marries and is not a virgin is a slut. I am saying that the current generation of girls are encouraged to act and dress like sluts. Having sex with people you barely know and have no committed relationship with is the very definition of slut.
And such behavior leads to great suffering, even if it's hidden beneath bravado and "cool".
There are very good reasons why every religion in the world (monotheist) values chastity before marriage and fidelity within marriage. Husbands and wives can form a loving, lifelong bond much better when each of them is the "first". Sex without lifelong commitment is animal life.
Ditto for the current generation of "boys."