Well, out of court settlements (mediation) are arbitrated based on the expectation of the ruling should it go to court. This is to save time and money. So most custody cases are influenced by the same bias in the court.

The bias exists, however, because of a reality; women typically make better custodians of children. I think men who complain about custody are barking up the wrong tree. Most of the time, if they really care, men can coparent and be part of their children's lives. This is why working towards an amicable divorce is important. There really is no escaping having a relationship with your ex if you have children with them that you care about.

The real problem for men is when resentful women use their custodial powers to harm their ex. Yes it happens, it's called Parental Alienation Syndrome (PAS). Denying it is kind of like #notallmen. This can be damaging to everyone. (including the woman) I tend to believe that most women divorcees will try to do what is in their children's best interest. Divorced men and women tend to snipe at each other from time to time, but that's a far cry from PAS.

Finally, Feminism is a movement that seeks to achieve gender equality through the advocacy of women's rights. While many feminists my genuinely care about men's issues, Feminism does not. It's not about men, nor does have to be for me to support it. There are issues that men face that Feminism cannot address.