I finally watched this over the weekend, and yeah, a turd is indeed a very fitting description for my experience with it. After all, a turd is the end result of digestible material being broken down and transformed into undesirable waste.
For me, the concepts in this movie were so full of nourishing potential, but were moved through with plot logic so inconsistent with itself that the end result is just broken apart and repulsive remnants of what had been so full of conceptually fresh and nutritive energy. A turd. That's so perfect! Beautifully done, jye!
But now reading through this thread, some here seem to insist that the plot logic works just fine. If that's the case, I must've missed a ton of details.
If Kat saw herself jump off the boat, then the Sator she's returning to on that boat had already been killed. But if she remembers seeing a lady jump off the boat, yet keeps living with a very alive Sator after she gets onboard, then two different realities are playing out simultaneously. If Sator's death on that boat is supposed to represent a nexus point for branching realities, then Sator has to be dead in one of them when Kat gets aboard. She'd eventually realize he's gone permanently missing and get on with her life - including taking care of her son. But the Kat who murdered Sator will still be around too, and wanting a life with that same son.
At the end of the movie, Kat #2 is the one picking the kid up from school. Well, where's Kat #1? If there was no Sator to shoot her, then she wouldn't go missing at any point by being taken into the inversion portal. And if there is a Sator (some alternate one to make the causal loop logic work), then how does Kat #2 avoid him all that time?
Then there's more nitpicky questions of why oxygen conversion being reversed would be a problem, but not gravitational problems from an inverse spin and orbit. And how are sound waves being projected forward from inverted people to non-inverted ears? It seems this stuff is *supposed to* make sense since Nolan spends so much time providing exposition on the logistics and "science" of this world he designed. And that's why it's a problem for me.