The trouble is that it's the foundational ideas that people find weird and difficult. Functional programming is still niche and so both immutable package installations and nix-the-language don't build on what people already know.
I hope that'll change over time, because yeah, the foundations are /so/ powerful, even today.
I learned F# before ever touching Nix. And it's not the functional nature that's the issue, rather the terse syntax, sparse documentation of plenty of special functions you need, and so on that make it an issue.
It's hard to find out how to do things, and often you find two examples with a partial solution that each use a very different incompatible way to get there.
I think the core idea of Nix is good, but we need a decent programming language designer to have a go at a new language for packaging.
Well, if you're comfortable with functional programming, that's great. Seriously, awesome! But you're in the minority.
Hard disagree on the "decent programming language designer", though. Nix-the-language is beautiful. It's tiny, with a minimum of concepts to learn, and very simple, regular syntax. At the same time, it's not so spare as say, Lisp or Scheme. It's really good. The implementation of that language could use some work - interpreter speed and debugging tools come to mind rather quickly.
I think the problem you've encountered is nixpkgs. It's a huge, sprawling code base with a lot of legacy code and a number of paradigms that were enthusiastically adopted and then later supplanted. In contrast to the language and tools which are well documented, there's basically no documentation, and what little there is hasn't been kept up-to-date as things change.
Still though, I think the biggest issue facing nix users is that the rest of the computing world works on the assumption of mutable software installations. The way pip assumes that the python interpreter and the python packages that have been installed are locked in a death grip drives me nuts. Even if you don't go full nix-store, could we at least separate those things? Even node gets that right.
>he way pip assumes that the python interpreter and the python packages that have been installed are locked in a death grip drives me nuts. Even if you don't go full nix-store, could we at least separate those things? Even node gets that right.
On this I definitely agree. Like I said I do think Nix is the right thing to do, I'm just thinking the how could be better.
I hope that'll change over time, because yeah, the foundations are /so/ powerful, even today.