No, I'm not twisting your words.
You said they shouldn't piss in the shower because the shower wouldn't be clean. The shower does get cleaned. People clean showers, you have to clean your shower. You assuming that the shower isn't cleaned, makes it sound like to you, not cleaning the shower is normal.
You should be cleaning your shower as often as you do your toilet. With bleach and everything. The human body is nasty, when you shower - skin cells, feces, urine, hair etc - get all over the shower. Just because you can't see it, doesn't mean it isn't there, but as long as you don't like the floor... you're probably gonna be fine, it'll just smell after a while.