We use node at work now. The fact is it's not worth it trying to get everyone to write good bash scripts. Js doesn't have nearly as many foot guns and there's a library for just about anything you could want to do.
True for async code, but if you use something like ShellJS [1] (which would be an easy way to rewrite a bash script that was getting out of hand), all commands are synchronous, so error handling is just try/catch.
If only everyone used promises...I can dream, right?
Regardless, I'd actually prefer Haskell's do-notation for both asynchronous commands and shell-scripting tasks. Even though Haskell isn't my favorite language, do-notation is quite nice for this.