I'm not against Rust. I'd like to see something less dangerous with memory than C, but I don't think it's time yet for the kernel to leave C.
It's pretty clean, stable, it's working well at the moment and the C language (or variants of it) is/are still actively used everywhere. I think the kernel universally going Rust will be a long road of everything under the sun going there first before it's ported in earnest.