A continuing pain point for Atomic users is the need to create a custom image just to add a `/nix` mount point in order to be able to use `nix` on their systems. So it seems to me if we could just provide it by default it would make life easier with no real downsides I can see. Since the root fs is read-only `/nix` can only really act as a mount point (it could even be made permission `000` perhaps). Since the nix package manager has now been [added](https://fedoraproject.org/wiki/Changes/Nix_package_tool) to Fedora during the F44 development cycle (including `/nix`), it makes sense to consider this now. Though the mount point can also benefit those that continue to use the upstream nix installers (since they would no longer need to use a custom image). I intend to provide an optional nix bind mount (of `/var/nix`) through an rpm package which Atomic users in particular could also use to bind mount to `/nix`.