They would then use these 2x4's on men. A quick, hard hit to the back of the head.
Then, perhaps, men would get it when a woman was interested.
But we don't live in a perfect world, so men are just destined to fumble about, never realizing that women are interested.
Of course, if they all had 2x4's, that would probably still not be enough. Maybe railroad ties would be better?