The question is not if Rust is more expressive but if C is expressive enough for the Linux kernel. So far there is no evidence that Rust adds any value here. And if C is missing certain features, they can be added. It looks like ISO is looking at that very thing in C2x and beyond.
C might be enough, but Rust is better.
Rust makes programming more productive. Are you denying that?
And C is not going to get Rust features: C's philosophy to stay limited on purpose.
The question is not if Rust is more expressive but if C is expressive enough for the Linux kernel. So far there is no evidence that Rust adds any value here. And if C is missing certain features, they can be added. It looks like ISO is looking at that very thing in C2x and beyond.