Nix is different, unapologetically so, that's the issue. And if it had to be more orthodox to win over a few more itinerant users that would make the whole thing pointless.
Ultimately I want less complication in my life, not more, and Nix very much does not provide that from what I can see.
Having said that, wouldn't you agree that same recipe-book approach is also true for traditional system configuration/administration?
But the thing about Nix is that it just adds even more complexity. As was mentioned elsethread, in order to be effective with Nix you need to understand all the complexities of Nix and Linux. And the thing about Linux is that we have a ton of adequate recipe books out there already.
Nix offers a way to easily customize and override said "reasonable defaults" across packages written in different programming languages and compiled using a variety of build toolchains. Doing so requires using a common language for expressing defaults and overriding them. IMO, that is not adding complexity, but taming it to make it reasonably easy for individual developers and teams, small and large.
I'd argue that the traditional stack relies on way too many tools, each designed for a limited purpose, and making a LOT of assumptions about the target system. This IMO is far more complex than learning one language and framework.
It absolutely doesn't. I'm someone who is fairly fluent with Nix, and in comparison the complexities of running a non-trivial docker-compose setup gives me nightmares. Luckily I basically never have to worry about that though.
I like to compare it to fossil fuels and global warming. Traditional systems get one started quick, but eventually build a large fragile system that gets harder to fix/rebuild the longer it goes on.
Nix is different, it forces you to do your work upfront. But once setup, you pretty much can (and to my attestation do) forget it is in place. You do have to learn setting a anything a and everything. But you only do it once. If the house burns down, you don't need to remember what you had. You don't need to remember what to setup in what order. You don't have to find out you forgot something in the middle of something else. In other words, the onus is no longer on you.
That last sentence is incredibly liberating. I stopped worrying having black screens after updates and pretty much stopped having rescue disc, because rescue functionality comes built in the system. It sounds cultish, and it kinda is, but as I said in previous comment on Nix, it is the worst system management tool, except all the others.
Nix takes a very different approach to system configuration than the traditional ways. Because it treats the entirety of the operating system (bootloader, kernel, user-land, services, account management, etc.) as a single composable unit, it is forced to break some old rules that date back to the oldest days of Unix and are (now) considered to be written in stone. The deviation from the Unix Filesystem Hierarchy is, IMO, required to make systems more composable and maintainable, and is inherently a good thing in the long run. Portable development environments eliminate "works-on-my-laptop" scenarios and ensure everyone on the team is always in sync with each other and CI/CD. Reproducible builds that can be rolled back after a botched deployment are a huge win. And delivering all of these features in a single tool requires breaking some of the old rules, and that is always met with resistance due to the inertia of "it works fine for me".
To be honest, there is no reason why you should give up what works well for you. Having said that, for those that are looking beyond the traditional tools like shell-scripts, Ansible, Chef, Puppet, and others, Nix offers all that is needed to easily build and maintain composable software stacks. Docker comes close to delivering some of the same features as Nix, but comparing the two is a bit like comparing system configuration using shell scripts to Chef/Ansible.
Yes; one does have to learn a new language and its idiosyncrasies. But that is also true of things like Rust. As a seasoned C programmer, I am able to write "good" C code. But that is not a statement about C's ability to scale to larger teams. Rust requires developers to give up their old ways of thinking and "give in" to the Rust-way. The longer you fight the borrow-checker, the more painful it gets. But once you give in, you are able to write code that is safer for use within large teams, thus delivering more momentum in the long run. It is not that it can't be built with C; it requires a communal way of thinking about software complexity that is forged by experience and tempered by camaraderie, and tools like Rust and Nix are excellent supplements.
I do agree with you that the documentation leaves a lot to be desired. I've always considered the FreeBSD Handbook to be the gold-standard for technical documentation and Nix has its work cut out to reach that stage of maturity. But I have full confidence in the Nix community's ability to deliver.
On the other hand, one of Nix's greatest strengths is that in many respects, its innovations are conservative. It brings software building and distribution forward in terms of reproducibility and isolation (like containers do) but (unlike containers) also retains the traditional package management virtues of granularity, efficiency, and sharing common resources (dependencies) when possible.