[xyproto]

Without having properly tried it either, my general impression is that the pitch goes a bit like this:

If you love Haskell and wants to make everything that has to so with packages on your system more like Haskell, Nix's got your back.

[aliasxneo]

Because it's functional? I've been using Nix in production for six months and I have no desire to learn Haskell.

[pxc]

Playing with Nix did increase my interest in functional programming, which was very new to me when I started using Nix.

But I've never gotten around to learning Haskell, and I don't think Nix is just for FP people.

[otabdeveloper4]

Nix is nothing like Haskell.

The store is built on standard Unix primitives ("worse is better"), and the core language is basically a stripped-down Javascript reskin.