I personally really wouldn't want the Nix community to end up being "those people who roll into any thread about package management yelling at people". Thankfully, for the most part that isn't the case right now, so let's keep it that way.
On the topic itself: yes, I think that everybody who's working on a package manager could (and should) learn from the work that's been done on Nix. Particularly the LISA paper[1] is a good and accessible read on why Nix works how it does, and what problems it solves that you might run into with your package manager project.
That having been said, that doesn't mean that there cannot be competing implementations. The important thing is ultimately the package management model, not the implementation, and it's no secret that Nix's implementation of the model has quite a few usability and documentation issues. Those might be easier to solve in a new implementation of the model.
In the end, everybody's working towards the same goal of better package management. So let's default to a constructive attitude towards other projects in the same space, rather than a tribal war.
[1] https://nixos.org/~eelco/pubs/nspfssd-lisa2004-final.pdf
Nixpkgs currently contains:
- the linux kernel (and supporting bits+userspace to build an entire bootable OS installer/disk image/PXE payload, etc)
- tens of thousands of Linux packages (many of which also work already on Darwin, where applicable)
- thousands of native {Go,Python,Haskell,Node} dependencies
If half of the effort that has gone into Linuxbrew and other efforts like this, went into nixpkgs, it would probably have even more packages and Windows support and we could stop inventing a new package manager to rule them all every 6 months. Insert XKCD joke here.
edit: -1, zero replies, years of being here and nothing changes. gotta love it. Maybe do more research next time instead of NIH?
edit2: I'll donate $500 to the charity of your choice if you can show me a "universal package manager" that contains more packages than nixpkgs (which has existed for ages at this point). I'll wait.