Based on https://go-review.googlesource.com/c/go/+/3012?tab=comments , it sounds like they were originally focusing on _clearer_.

(I interpret that) rsc considers the native binary operators to be clearer than a function with the name `Compare`. Honestly, I'd expect people to use `==` as well over `strings.Compare`.

`==` _does_ work for strings, but I believe `[]byte` would try comparing memory addresses which is why the `bytes.Compare` version exists and is optimized (some assembly version, probably costly to maintain per arch?).