When most men don't want custody to begin with. I mean, it's not because of biased laws that you are treated unfairly. In most cases, when a man wants custody, courts usually give it to him over the woman. If anything, women are treated unfairly in custody agreements. Why do men ignore the fact that most fathers would rather not deal with the sacrifice and responsibility that raising a child takes?
@YES Indeed: You are too funny. You have to drag in alimony, that is very rarely awarded anymore, to make a point. Guess that shows how weak your argument is when you have to drag that old gem in.

Jonus: I know it conflicts with your personal experiences and what you've observed, but according to family lawyers, who witness custody fights on a regular basis, men usually win custody when they are determined to fight for it. The point being, they usually don't want it.