Furthermore I do not think you can compare Guix to Nix for commercial work as Nix is LGPL [2] with the packages being MIT [3] where Guix is GPL [4] allowing for Nix derivative work to be used commercially with little restriction.
I wish Guix had stayed as a guile layer for Nix and not gone off in its own direction because of the licensing ambiguity (as far as I can tell this is the reason) in Nix packages. If anyone has more insight on why this split happened or the possibility of making such layers for Nix I'm very interested in this topic.
[0] https://nixos.org/learn.html [1] https://nixos.org/nixos/packages.html?channel=nixos-19.09 [2] https://github.com/NixOS/nix#license [3] https://github.com/NixOS/nixpkgs/blob/master/COPYING [4] https://guix.gnu.org/about/