Why? Because you predict it won't meet your definition of popularity? Once upon a time, Arch and Gentoo were dismissed in exactly this way.

Arch and Gentoo are still tiny fractions of the linux install base (which is itself a tiny fraction of users), and are mostly irrelevant.

Unless you feel that those that write software have more influence in the direction of the community than those who just apt-get/yum install it.

Then they are a small fraction of users but are not irrelevant.

Irrelevant for what, to whom? Everything is a tiny fraction of something -- are you saying that value is purely a function of popularity?

Perhaps it doesnt matter, if this provides a large enough software base, then fedora, arch, gentoo etc would perhaps just write a guix->(dpkg|rpm|...) converter to keep their distribution up to date. Not sure if it would be possible but moving work upstream where more detailed and in-depth knowledge is available might be a good thing.

with guix/nix you don't even care if they get adopted or not. you can use it in coexistence with any package manager.

very common scenario i come across few times a year: you get to work on an old CentOS/RedHat/Fedora box but you need to install latest package X which is only in next version of current distro. which would mean you need to upgrade or do a lot of manual work. with guix/nix you just install it without need to upgrade.