alt Hacker NewsI can think a few reasons:
- Cranelift applies less optimizations in exchange for faster compilation times, because it was developed to compile WASM (wasmtime), but turns out that is good enough for Rust debug builds.
- Cranelift does not support the wide range of platforms (AFAIK just X86_64 and some ARM targets)
So it isn't just a matter of "they would use Rust instead".
There is a whole ecosystem of contributions across the globe and the lingua franca used by those contributors.