This is really unfortunate. Unless you invest time into learning which paths to walk, you're not going to have a great experience with Nix. That just doesn't scale to modern engineering teams, you can't expect everyone to know everything.
> Plus, a coworker pointed out that while its supposed to be pure and functional, many recipes still basically wrap a shell script. So its not that far from the build system we already have...
It's true that a lot of nix expressions boil down to a shell script. But by default they're running in a sandboxed environment that can be exactly replicated and guarantees (mostly) reproducible results. And that's great - after some ceremony to set everything up, Nix lets you work with the tools you already know, but puts them into a reproducible environment.