yeah applying this to art seems like a silly idea, a good ending can save a bad thing, like the secret good last sherlock episode

also I think they're trying to refer to the sunk cost fallacy, but that's not the case in their example, the sunk cost fallacy is about bailing before spending more money but after having received the results. In this case you haven't actually received everything you've paid for yet (i.e. the whole show), so it's not comparable.