Katz does himself a great disservice by suggesting that the issue of domestic violence belongs to one gender or the other. He offends some of the men his plan depends on when he says that domestic violence is a men's issue, that men are the problem, or that men are the ones who need to fix it. He offends them, not because they are awful, abusive men, but because they are not and hate being lumped together with that ilk simply because of their gender. Katz mentions that feminists have been labeled man haters; well, this is part of the reason why. To suggest that terrorism is a Muslim problem that Muslims need to solve is very inappropriate, what makes this any different?
When people perceive that they are being unfairly blamed, they become defensive and far less receptive. Katz made things much more difficult for himself by framing the issue in the way he did, which is unfortunate because some of his ideas were decent. I can't help but wonder whether Katz was actually trying to inspire men to become part of the solution or if he was just telling women what he knew they wanted to hear. Perhaps I'm just a cynic.
As for how difficult it is to challenge other men, it depends on the situation and what is being said. I'm usually willing to give people the benefit of the doubt and assume they were trying to be funny and don't really mean it. I've made a couple tasteless jokes with friends that I wished I could have taken back; it is bound to happen occasionally if you have a dark sense of humor. Sometimes you know for sure they mean it, in which case it is almost never worth it to set them straight. I'm willing to stand up for someone else who might be offended, but if no one else cares then it just isn't worth my time. It is no secret that men who beat their wives are considered to be human garbage by the overwhelming majority of this and all other civilized countries. I don't think correcting people for saying sexist things is going to end domestic violence.