On Directing Film by Mamet, why would a writer read this?

Commercial fiction writers are always being subjected to the next big thing that will ensure success. Trends of "what you need" come and go. The Writer's Journey; Goal, Motivation, Conflict; How to Write the Breakout Novel (with workbook) just to list a few. Every one of these books contain great stuff that can in fact improve writing.

I recently came across another book many writers read in hopes of improving their writing and making it more commercial, more marketable. This one struck me as different because until many of others I've read it focuses on only a small piece-the arrangement of scenes. Mamet encourages the storyteller, the director in this case, to virtually eliminate backstory and use a collage of uninflected,  juxtaposed images (scenes) to let the story tell itself.

I'm still trying to sort out what I think of this approach as it relates to fiction writing, commercial fiction writing in particular. There is a wave of conversation in the commercial fiction world about intentionally creating unstructured characters to provide the reader with a more satisfying experience. Mamet's approach would support the concept of reducing character interiority and backstory. But in doing so, does a writer risk creating flat, underdeveloped characters and delivering a flat underdeveloped story?

If you're looking for something to stir your thinking, I suggest this little book. It can be read in a couple hours. Perfect for a plane ride or rainy afternoon.

**Yeah, I think I just made that term "unstructured character" up.