That's part of the problem. Every man that doesn't press charges when assaulted by a woman is one less showing up in the statistics Men are afraid that if the cops get involved, the man is the one who will be arrested and charged, regardless of the true situation. Thus, it's best to walk away from the crazy woman.
I understand that the system is stacked against men, largely the doing of men BTW, but men can get justice. I know of men who have filed criminal charges and won. I know of one in particular who was abused while falsely accused of abuse, who not only beat those charges, but got a restraining order against her. Why? Because he had someone who stood behind him (me).
I know from experience that abused men can get justice. They just have to try, and their male friends need to support them rather than laugh at them.