I think there are three levels or stages of story:

1. We all have a mass of undifferentiated stories churning around in our body (say in the stomach — it’s certainly not a cerebral storage facility, more of a visceral holding tank).
2. Something happens to dislodge a chunk of story and it appears in our thought processes (brain?) as an idea (not as well-defined as what we mean by “concept” or “logline” — more like a feeling or a hunch. When someone at a party says to you “You’re a writer? Hey I’ve got a great idea for a movie!” this is probably what they’re referring to. The writer develops this story using whatever methods / techniques (aka the craft) are best suited for making the story a successful read.
3. Ideally the story is bought, and it becomes edited / rewritten if necessary, cast, acted out, photographed, scored, etc. and then the script story becomes the film story that the audience sees.

As your post points out, the craft for a writer exists only for the sake of the story (in Stage 2 to provide a satisfying read, in Stage 3 to provide a satisfying viewing experience for the audience).

I know there are stories to the contrary, but it may well be the case that most professional readers don’t care about craft if the written story seems as if it would make an engrossing movie. I’ve read amateur scripts in which the writer used various techniques (e.g. a flashy Shane Black aside in the action paragraph, or lots of fireworks in the first few pages) to make the reading experience more interesting or unique. But if the craft doesn’t contribute to the reader’s anticipation that the script would make a satisfying film, then there’s no reason to recommend the script for the next stage.

This doesn’t mean that bad writing is acceptable as long as the story is good. What makes bad writing bad is that it interferes with or doesn’t contribute to a good story. As the philosophers say, the craft is necessary but not sufficient. Unfortunately, the gurus from the Advice Factory often promise that the craft is all you need (i.e. the craft you learn from their book or seminar).