It looks like the bigger question here is this: Is it the official policy of the home-assistant project that their software should not be packaged by NixOS? frenck is the fourth most active contributor to home-assistant - and it uses quite a few libraries he has authored: https://github.com/home-assistant/core/graphs/contributors If frenck is saying NixOS can't package his libraries, he's actually enforcing that NixO…
I have the impression that it is the policy of the home-assistant project that their software should not be run in any way not supported by them, and not redistributed by any distribution or other third party. They're somewhat actively hostile against people not following that.