No, totally wrong. C programmers in Linux do not NEED to learn or master Rust. They just need to cooperate. The problem is, that some C programmers refuse to cooperate with Rust. They just want Rust to disappear. That has nothing to do with mastering the language. They refuse to make changes to their C code, so it can cooperate with Rust code via bindings.

I would argue that's not the biggest problem, the biggest problem is that for you to refactor a function to work with rust, you need to refactor all the subsystems that rely on that function, and that take time, and you need to explain for the C dev why it need to be done, try to explain that for the amount of C devs in the kernel