It’s whole deal is “declarative” system configuration. Essentially, it means if your config file is identical to someone else’s, your systems will have identical software/dependencies, and everything should, in theory, run the same, generally speaking.
So for instance, to install a package, instead of running sudo apt install nameofpackage, I would just edit my NixOS config file to have the line pkgs.nameofpackage in it, run a command to “rebuild” my system using sudo nixos-rebuild switch, and it would automatically be installed.
That’s not the whole of it of course, but that’s just a general overview. It’s really good for if you’re running multiple systems that need the same software, because all you need to do is copy the config file over, run sudo nixos-rebuild switch, and the systems now have identical software.
Oh yeah, and you can also easily rollback. If you break anything, you can, while starting to boot NixOS, just select the previous configuration, start your system, and any changes you’d made to software/settings will just be undone. It’s great for troubleshooting.
AFAIK NixOS also has the largest number of supported packages out of any distro.
Because when the norm to these people is media that exclusively panders to them, even one single piece of media that doesn’t represent them is a zero-to-100 change. Going from even 0 to 1 piece of inclusive media is startling, new, and scary to them, because they’re simply not used to it.
It’s the root of the entire conservative mentality (which is why you’ll primarily see conservative men talking about this) since all conservatism is based in a desire for things to remain the same. Change is just scary to these people, no matter how benign the change may be.