“Why is a normal biological function weird to you?”
Usually I get to not watch it.
See, pretty much every major Hollywood film released in the past two decades has somebody pissing or refers to somebody pissing. Sometimes there's visible pissing, sometimes a character pisses themselves or mentions the possibility of pissing themselves, sometimes you get piss sounds while someone's in a bathroom, sometimes there's piss in a room (such as in the second
Hobbit movie, where a dude empties a chamber pot and the contents blow back into his face) and in some films, such as
Argo ("Yeah, I took a leak next to Warren Beatty once") or
True Grit ("He's tendin' to his necessaries") piss is only mentioned as a thing that occurs. It's hard to find a big movie that doesn't have something like this. I don't know why, but I'm guessing it's writers' and directors' way of reminding the audience that
yes, we are aware that bodily functions are a thing that exists and/or that
our characters are in fact human beings with bodily functions; despite how much makeup they're wearing they're not actually Barbie dolls.
However, in almost every movie whose production isn't run by a lunatic, the piss reference happens once and never again. Exceptions do exist, one being
The Green Mile, in which a urinary tract infection being magically cured factors into a character's story. But there is nothing noteworthy or special about bodily functions and they're kinda gross, so movies tend to just note that bodily functions exist and then hurry onward toward things that actually matter to the story. If bodily functions
are central to the story in some way, that's generally a situation in which the writer needs to think long and hard about what the fuck they're doing.
Where movies are filmed by insane people, however, you sometimes get this weird and shitty obsession with bodily functions. One example that comes to mind was a particularly horrendous Western film called
Shoot 'Em Up that was so amazingly terrible in every way that the forced insertion of the director's extreme breastfeeding fetish only barely managed to be the most memorably awful thing in the movie. In non-movie examples, you have the video game
Heavy Rain, which manages to include a piss sequence or some other depiction of pissing in
every fucking scene.
So yeah, this Melinda Scott-esque "it's just a bodily function why are you being so weird about it, I only talk about it obsessively at every opportunity" schtick is pretty shallow.