What about books? Those are artistically designed to be books, but are adapted to film regardless. Are all movie adaptations to be ignored on principle?
This is not the same thing. Adapting basic stories to different mediums is a subject that has nothing to do with this conversation.
How? And who says the story adapted is basic? That ignores the nuances and thematic depth a work might have, much like how a movie can ignore such depth or enhance it.