After watching this I felt like Nolan had a picture in his head of a battle showcasing half the soldiers moving forward in time while the other half does things in reverse and then tried to hide the fact that he had absolutely no other backstory whatsoever by burying it under the notion that since the "protagonist" doesn't know what's going on (EVER!) that the audience won't feel like they should know either.
I have a hard time picturing that being the case. I can't see Nolan spending five years (yes, five!
) writing this screenplay just to construct a flimsy story in order to put a visual idea on screen. Instead, I think he got completely mesmerized by the concept of reversing entropy and how it would manifest relative to the observable progression of time. I feel that he mainly wanted to put the concept itself (not necessarily the superficial/visual applications) on screen.
This has become Nolan's defining characteristic: He isolates fascinating concepts that clearly intrigue him, and then he attempts to explore them in a way that can still be able to captivate and *entertain* mass audiences. The problem is that these concepts aren't the type that you can use Cliff's Notes with in order to effectively implement them into a narrative for a feature film.
Much like with Inception and Interstellar, I thought Tenet presented a truly outstanding concept that could be worthwhile as original and innovative material to build a movie around. These are concepts that have science-based foundations and potential future applications that can even legitimately change our understanding of reality. But trying to turn such concepts into entertaining motion pictures is a bit of a Herculean task that I don't think he conquered in either case.
For a filmmaker to do justice to conceptual material like this without turning his movie into a science documentary, he has to deftly weave it through the plot where character motivations, plot logic, pacing, and entertainment value aren't compromised by the inherent complexity of the premise. For me, Nolan missed that mark with Tenet even more than with Interstellar, and certainly more than with Inception.
But in no way do I think the film's shortcomings were the product of laziness or failure of vision. I think its issues came from Nolan struggling to force entertainment value out of a concept that he knows has plenty of intriguing intellectual value but isn't easy to convey. Providing accessible and compelling entertainment isn't easy on its own, but doing so while bending minds gets trickier. In fact, it just makes it easier to create a mess out of plot logic and character development.