> That said, this should just be a shell itself and not something that generates into other shell dialects. Otherwise, why not use Ruby or something like it that has actual expressive power?

I'm guessing the advantage here would be that the compiled "bytecode" (the resulting bash) can be distributed to systems that would then not need to have Amber installed. (And vs. a real binary from, e.g., Go/Rust/etc., it isn't tied to the platform, either.)

Vs. a Ruby script would require Ruby as a run-time dependency; Amber here is effectively a compile-time dependency.

Python 3 is available basically everywhere these days though, so I think there's still a lot of merit to just using a higher level language like you suggest. Even Ruby, while not available out of the box, is not exactly hard to get on most OSes.