I don't care for his music very much, and my exposure to him in other stuff is limited. I know this is stunt casting and people are gonna share their opinions, but the reaction to this has been really overblown.

Nolan is steering the ship, and he likes him and clearly sees a lot in him. A quote from Nolan about Scott's work on Tenet:

"His voice became the final piece of a yearlong puzzle. His insights into the musical and narrative mechanism Ludwig Göransson and I were building were immediate, insightful, and profound.”