I'm not an expert family law but I think we can agree that courts are terrible, expensive and sad places to sort out family conflict. 50/50 parent legislation would force just that. When parents don't get along kids suffer. Passing a law doesn't work for kids.
As for family violence, the vast majority of "perps" are male. That's a statistical fact borne out by #'s collected by police and hospital professionals. 
That's not feminist ideology that's fact.
In a perfect world, I agree that more resources should be allotted to deal with trauma to treat everyone afflicted.