A detailed answer won't be a short one but the main idea is that men have traditionally been viewed as dominant and tend to give the physical abuse to women that is evident from the outside, especially in certain cultures. For a while, a woman had to report the abuse to the police in order to have them charge the male, even if they see the abuse on the woman. After the Feminist Movement, things began to change and lots of the focus was on women. However, it's wrong to say only men do the battering or abuse, women do too. I think part of the reason why it's not brought up as much is because the man may feel that he's mean to be able to take this because that is what society has socialized; girls are socialized to be more dependent, less dominating, etc... .

The issue about emotionally abused I think many people accept and possibly physically (probably more accepting of indirect physical abuse). As for sexual abuse, for a while the laws and views, which still remain present today although there are some changes, state penetration must occur and due to the human anatomy, women cannot do this. Obviously this view has been criticized to death of have sexism written all over it and so it's been torn down but still is prevalent.

I'm finishing a course in forensic psychology and males being abused does happen quite a lot, probably actually the same amount as women do and the research supports this. Unfortunately, the methods of abuse may differ along with the duration, severity and location of abuse. It's come to a point now where if a woman reports abuse to police, the police are more likely to believe it because women are generally seen as less physically dominating. Sadly, this is a false notion because you don't need to be physically stronger to abuse someone.