Because hitting a woman with your bare hands is wrong and, simply put, not done.
One should always use a blunt object when hitting a woman.
Preferably a tool of some sort.
The word 'wrench' comes to mind.
Repeatedly.
You know, it always bothered me that I didn't have the dialogue option to expose myself to Frank Horrigan before killing him. Ah well, the mutated toe will just have to be my surrogate.