I sincerely think that there are generational differences that make this hard to explain (thanks gender roles!). Mine stood on the edifice of the changes, whereas yours more than likely came after. Thank God for progress overall, but sometimes the progress takes ugly forms and I don't even believe in God.
I'll put it to you this way. Many months ago, my asshole dumbass uncle scared the shit out of my Mom. He didn't threaten her but he made it difficult for her to leave. Now, big as mr. farside character is, he doesn't scare me, because I know he's a huge pussy and I could kick his ass if I needed to, and I can't kick anyone's ass. But my Mom is a single woman who has been physically abused. And a very large 6-ft-plus man does not put himself in a position to scare a tiny single woman. Ever. You're out of the man club. Might as well start getting a mani-pedi every week and attending metrosexuals anonymous, 'cos you're out. Women are targeted because they are perceived as weak. As a child, I was targeted by bullies because I was percieved as weak. I can forgive that; they were just kids. For an adult to do that makes them a predator, so fuck them.
This of course does not forgive batshit or opportunistic women who think that violence is a good idea. And, as much as you may find it hard to believe, I think a lot of traditional gender beliefs are beyond antiquated. But a woman hitting a man, while never justified, isn't a part of a larger phenomenon wherein women have decided as a group that men are weak and therefore they can take their shit out on them. That, and I have punched a woman in anger twice in my life, not counting rough stuff with my older sisters growing up, although one was very strategic and frankly I'm proud of it.
But I still look at how a man (because I AM one) treats his woman, physically, as one of the highest measures of who he is. You don't have to hold the door open, but you also don't pound her face in 'cos your boss yelled at you today.