But it seems it isn't able to blindly mirror stuff from pip, for example? Or to just package any linux under the sun, like Docker can? You'd have to have a nix-specific version of every package you want to use.
And then, the first time you hit upon a package it doesn't have, you have to develop and maintain your own version of it (as far as I understand?). This sounds like a lot of work for someone who wants packages to just work, so they can focus on other things.
I remember using freebsd at some point. The annoyance of not being able to just grab a deb from random sites and install them far outweighted any benefits I got from a cleaner OS organization and some extra features. Nix feels the same way.
I am not saying nix is a bad idea or that it'd have no benefit. Just that, for non-enthusiasts and non-early adopters like myself, it's dead in the water until there is some major support behind it.