I think the other side gets it wrong when they treat a story like it's just information. It's more about the ride, and if someone tells you the ending, that ride is kind of gone. Maybe people can still enjoy it, but something feels missing.
I read somewhere that most people say knowing the twist ruins the story for them, which surprised me. My opponent seems to be agreeing, so fair enough, maybe that helps my side. I still just feel like the surprise is the whole point.