A misfire from Nolan?
It certainly seems that way.
The critical and audience reception is all over the place it seems, and certainly far from the critical darling that most of Nolan's previous movies have been.
The only ones giving this the highest of praise are hardcore Nolanites on the bandwagon - long-time purists who insist he can do no wrong!
The most common criticism seems to be the incoherent plot. I know Nolan's no stranger to complexity and experimentation, but at least movies like Interstellar managed to be somewhat comprehensible and intriguing - even if a second watch may be required to fully "grasp" them.
I, for one, got none of that from Tenet. It was just an overlong, cacophonous mess without any humour or engagement and I felt relieved when it was finally over.
I watched this with my brother. He's not a hardcore Nolanite by any means, but he's an avid fan of Momento, Inception, and Interstellar, yet he also disliked this to a great deal for the same reasons I did.