[jacobolus]

Because you don’t like the smell? You’re afraid other people will think you are gross? You have been trained to fear pee?

In normal circumstances getting urine on skin (or drinking small amounts of it for that matter) is not going to cause you any health problem. Urine contains various toxins your liver removed from your bloodstream, so drinking large amounts of it might not be the best idea.

Modern American (and possibly other) cultures have various taboos around cleanliness, including disgust about pee and peeing. But often these are not based on serious health fears.

Don’t pee on wounds though. Urine is not sterile. https://www.sciencenews.org/blog/gory-details/urine-not-ster...

[amanaplanacanal]

Actually, if you are just using the bathroom to pee, you should probably wash your hands before you go, as your hands are usually "dirtier" than your genitals are.

[jazoom]

Dark and moist genital area is a much better breeding ground than light-exposed, dry hands. I assure you there are microbes down there.

[GrinningFool]

Though interestingly, it can be according the article's summary of the study?

    More than 70 percent of the urine samples contained 
    bacteria, including at least 33 types of bacteria 
    (at the genus level) in normal urine. 

This suggests that 30% were sterile.