Why isn't genital battery recognised as a form of ual ault?

If I'm in a fight with a guy (a real dirty fight) I'd aim for where it hurts, the most logical place. Not because it's 'ual', but because it will hurt him. The case can be argued this way. However, I think about a TON of y stuff and battery of the male genitalia only comes to mind 25% of the time, maybe once a week not even. But now you've got me thinking about it...