I walked in on that the first time I ever used a public gym and that shit is seared into my memory--that was enough to turn me off of the locker room for some time and you know what, I don't miss it.
More often than not, pub[l]ic nudity is innocuous, nothing remarkable, but there will always be the outlier that spoils the rest of the bunch by doing weird shit with their genitals, be it drying them where theyre not supposed to be dried (see above), touching themselves in a sexual manner (seen it in a few different locker rooms, and of course the old naked men who are more than friendly to younger, naked men.
I for one say good riddance to the nude locker room. Fuck that shit.