Theater As The Last Bastion For The C-Word

Mamet, LaBute (see, for example, discussion about the two of them) and now Ethan Coen; three and it's a trend:

City Lights follows a butthead musician, Ted (Joey Slotnick), who spends an awkward afternoon with Kim (Aya Cash), a ditzy stranger, and her judgy friend Marci (Cassie Beck). Kim pursues Ted though she knows he's a "dream squasher." The play's nihilistic denouement — Ted drives Kim out of his apartment, bellowing "Cunt!" — meets only Neil LaBute's standard for nuance.

What is it about theater where playwrights feel obligated to beat audiences over the head with that one word that still shocks? You get the sense that in the recesses of a writer's mind, he or she (generally "he," it seems) defaults to the C-word because if it weren't for it, nothing else that happens on a stage would move people. It's sort of like, "C-word! Pay attention! Still relevant!" Did Ethan Coen — as someone who is primarily a filmmaker — subconsciously pull the C-word from the Mamets and LaButes before him?