I think that all the efforts to fix or re-implement the Nix language have vindicated Ludovic, the Guix maintainer, who chose an existing general-purpose language instead.
Except GUIX is more of a political project and part of the GNU "stack". It's a noble goal and I think it's great they're doing it. (It's people doing work on their spare time, so more power to them!)
But I wonder if that will help or hinder it in the end. It's also unclear to me what Guile brings other than fracturing the Scheme/Lisp/Racket community further (there are other Schemes that are older, seemingly just as clean, and often more powerful). Seems like mostly NIMBYism, but I might be offbase
The only significant shortcoming of the Nix language is the lack of static types. Guix doesn't fix this. In fact there isn't an existing language in common use that offers statically-typed extensible records, which IMHO vindicates the bespoke approach.
As I explained in another comment, Scheme is indeed dynamically-typed (like Nix), but it's also strongly typed: one can define new data types, they are disjoint, and there can be no casts and the like. In Guix "packages" and "operating systems" are different types, you get a type error if you use one instead of the other; in Nix both are "attribute sets" (key/value dictionaries.)
I think the one-type-fits-all ("attribute sets") vs. strong typing (disjoing record types) axis matters more than the static vs. dynamic axis here because most of the code (OS config files, package definitions, etc.) is loaded dynamically.
