Rust's leadership wanted a formal specification. They thought it's reasonable. Hence, why they invested in a team to build a spec https://blog.rust-lang.org/ins

Rust's leadership wanted a formal specification. They thought it's reasonable. Hence, why they invested in a team to build a spec https://blog.rust-lang.org/inside-rust/2023/11/15/spec-vision/ https://blog.rust-lang.org/inside-rust/2023/11/15/spec-visio... One of the founding members wrote a blog post & RFC which gives some good reasons why a spec is needed https://blog.m-ou.se/rust-standard https://blog.m-ou.se/rust-standard https://rust-lang.github.io/rfcs/3355-rust-spec.html https://rust-lang.github.io/rfcs/3355-rust-spec.html