I get what you're saying from a writers perspective (wanting to create consistency and really getting to the bottom of your characters and the world they live in in order to tell a well rounded, developed story) but in the context of this forum, the writer seems very much interested in pushing the story building to the forefront of the tale. So there is sort of a direct correlation between world building and story telling for their specific project. They feel the world building is relevant to the telling of the story which, I think (whatever that's worth), makes it apart of the story.
I'm the same as you in that I need to dissect my world and characters inside and out until they're basically real in my own imagination, complete with their own system of physics, geography and biology. Not to show off to the reader but just in order to tell the story to the best of my ability, almost in a way that it's like I'm accounting for a lost piece of history. Like you said, that is not the exact same as story telling, but the two are kind of symbiotic in that the story wouldn't exist as it is without such methodical and disciplined world building. They're like two sides of the same coin but the coin can only land with one side visible. I hope that makes sense.