Post History

I think that the answer, broadly, is that structure is necessary but not sufficient. You need both structure and vision. 

Yes, you can have works that don't follow conventional structures, or don't do so in obvious ways, but their appeal tends to be limited. 

It is also true that there are some readers who are less interested in the quality of the story than in how well it aligns with their political prejudices. But so what? Either you align with those prejudices or you don't, and chances are a good story that aligned with those prejudices would still sell better than a bad story that did. 

So that leaves us with the mainstream appeal, the appeal of story itself. And the structure of story can certainly be described and defined and detected in successful works. The definitions and the formulas can certainly be taken too far. If anyone is telling you that a particular even has to happen at the 62.5% mark of your manuscript, back slowly out of the room being careful not to make eye contact. But the general formulation of story structure, I believe, is fundamentally sound. 

But structure is not enough. You need another ingredient, and I believe that ingredient is vision. You need to see something interesting and compelling about the world and the human experience. It does not have to be a new discovery, but it needs to be keenly observed. Without this, your characters will seem flat and their motivations unconvincing. A story is an experience, and that experience is born of the vision of the author. A formula may tell you how the experience progresses, but a formula can't make the experience convincing in the first place. For that you need vision. 

Why don't the books talk about vision? Because you can't teach vision. There is no formula for vision. You either have it or you don't. I'm not saying you can't develop it, though we don't seem to know how exactly. Actually reading great literature may help a lot. It is notable how many of the most successful popular authors read the classics assiduously. Reading people of great vision may well be a way to acquire vision yourself. 

But if you don't have vision, no amount of technique is going to make your story compelling. The definition of formulaic, I would suggest, is a work that is all formula and no vision.