What happens is, after certain age the women start to think about a serious relationship because they want to accomplish certain things in their lives, like: marriage, having children, buying a house or getting status. Then, they start to opt for the good guy and they start saying that this is what they always wanted.
But in fact, what really happened is that they loved (and still love) some bad boy, but the guy just didn’t want them, and they had to figure out how to get their living in his absence.
This is the alpha-beta reality. Women are attracted by men who appears like alpha: dominant, confident, aggressive and powerful. All this traits can be found and bad boys and criminals (haha!). It is not rational at all. Some theories says it happens because these traits were more effective in pre-history when everything was solved by violence. But, when it comes to raising a family they look for the beta, which is the good guy.
This situation embarrass many men. Because, based in how we see this dynamics it sounds that is more worthy to be a bad boy than a good guy. Being a good guy you are not getting as many women, and after all you are being chosen by practical ways, not because they are really interested in you.
If we look at history, the marriage was a way created to solve the conflict that emerged by this behaviour.
In the past, men would always fight for everything and violence was determinant. The marriage secured that man wouldn’t be “betalized”, by determining that the woman would relate to only her husband.