a clean shower space is nice. feels good to get clean in the shower. feels good to have good hygeine.
piss does not feel clean. getting it all over your body does not feel clean. getting it over your body-cleaning area feels messy and stinky and pointless.
i guess i'm in the minority for some weird reason but i don't get the point of pissing in the shower or the kitchen sink or the living room or the fridge or your pants.