Kind of feels like the pitch meeting for this one basically went:
"So I was just reading about the idea of this 'Sin Eater' thing on Wikipedia the other day, it actually sounds really interesting, I'm super keen to put it in a movie!"
"Oh great, so what's the story gonna be?"
"I'm sorry the what?"
"The story. You can't just say you're gonna put a Sin Eater in 'a movie' you have to like... Actually make the movie that it goes in. What's the movie gonna be about?"