I think it's weird to most people. I've used NixOS on my personal machines for 2 years and Nix lang is easily the worst thing about it. I'm definitely not a huge functional guy but I'm familiar with Lisp/Scheme and F#. Nix feels completely foreign in a way that those languages didn't.
There have definitely been situations where I've just decided to not try out an application because it wasn't in nixpkgs (it's pretty rare for a package to not exist but one prominent example is Zen browser).