Rust is a systems language for people who prefer strongly typed languages. It has some relatively unique features that make learning and using the language a little quirky, but for many who end up liking it, C and C++ often no longer seem "just fine." Rust ends up being a genuine improvement for a lot of people.

Also, unless you mean "write an essentially new language that happens to compile to C rather than machine code" -- you're delusional if you think you can recreate some of the nicer features of Rust as a new C preprocessor.