A system's purpose is what it does. Nix the language is used to generate bash scripts that are then run in a sandbox, and based on what I'm seeing it's not a great fit/architecture.

(Nix is not a general-purpose language. The concept of store paths etc is hardcoded in it.)

I can complain about the horrible, undebuggable, error messages on the slightest typos too, if you want? Nix is way too subtle to "win the readability contest".