However, many people in game programming care about their craft and having as much control as possible and also being efficient with their resources. In this project specifically, there might be also some kind of nostalgia thing going on.
By the way, even though I use Python daily for ML and some web stuff, I find Python very lacking for serious, complex projects because of the dynamic type system, bad performance, and the infamous GIL. I find the idea that programming something in a system-level language is some kind of lost, arcane craft that shouldn't even be attempted quite perplexing.