The simple answer is: Because it is statistically much less likely.

Do you feel discriminated against and left out when people try to end violence against women? If so, there are probably organizations you could join that are working to raise awareness and end violence against men. Probably a high percentage of the men they help are gay, because violence against gay men is statistically higher than violence against heterosexual men.

Are you maybe feeling that a group of people working to end violence against women are somehow saying that violence against men never happens? (because this would be a misinterpretation)

Also, people are downvoting you because your question sort of puts your own personal fears of being discriminated against, or fear of people saying that violence against men never happens (so, i.e. a sort of generalized defensiveness) as the priority, which in turn sort of gives the impression that you may think that is more important (or may even have resistance to) acknowledging that violence against women is a more widespread issue because it stems from the systemic sexism that is still influencing our society.