The concept of virginity, particularly the idea that a woman's sexual history somehow determines her worth, was heavily shaped by patriarchal societies that used women's sexuality as a means of controlling inheritance, marriage, and political power.
The idea that an individual somehow becomes less of a person simply because she has had sex is absurd. A woman's value does not diminish because someone has given her a label or because she has engaged in a perfectly ordinary human act.
And then there is the glaring double standard. The man who had sex with her is often treated as some kind of hero, while she is supposedly diminished by the exact same act. He gets the bragging rights and the high fives; she gets judged for it.
So apparently a man's virginity is irrelevant, but a woman's is supposed to be sacred. Not the person, mind you. The vagina.
What a load of crap.