morbid validity
something horrible or morbid in the written word, on film, or in an image, that explains itself in a way you can understand and/or appreciate. creating something horrible or morbid that is not simply to shock, scare, or disgust people.
Some of Edgar Allen Poe's work, like the Cask of Amontillado, had a sort of morbid vailidity behind it. (or) I saw that horror movie, Final Destination, and it seemed that most of the killings were done to shock people, it lacked morbid validity compared to a movie like Silence of the Lambs.