When I said I'd even take lua over python, that's only if I was forced to pick a high level language for a shell. Lua is really easy to conjure up higher level algos, like javascript can.
But I'm not convinced any high level language is a viable replacement for bash. It would have to be more functional than bash whilst still having good support for standard unix tools.
One very interesting idea I found was a macro library for racket that turns s-expressions from deeply nested structures into a much flatter representation. Lisp might be a good option with toy with because of flexibility like that.
- no pipe/redirection mechanism
- high overhead in version/library control(pyenv, venv)