That's true. And, Apache, the databases, etc. are all challenging. But, one step at a time. NixOS is several steps ahead of what the rest of us are doing (my products run predominantly on CentOS, Ubuntu, Debian, with a small number running on FreeBSD and a few other outliers).

I'm pretty excited about rust based operating system experiments, though it'll probably be 10+ years before we can start using them seriously in production (and operating system kernels have a lot of unpleasant stateful things to deal with, so likely will never be particularly pure no matter what language they're written in).

Anyway, Nix is cool stuff that I think is interesting and novel.