Figuring out how to use proprietary software with Guix is a miserable experience. As a new, curious user, I was told: I won't receive help, I can't discuss it, I shouldn't use proprietary software, that Guix isn't for me.
This is not a welcoming response. It's not useful. It's hostile. It's zealotry.
Instead, a welcoming response would be to say yeah, that's unfortunate but understandable, maybe help educate why free software is important, and suggest a path forward, such as pointing the user to unofficial channels. By comparison, Nix excels here -- There is no hostility.
It's like being told by a mathematician that I shouldn't use math to calculate my taxes because taxes are unethical and illegal. Yeah that's nice, but I still have to pay them. I just want to calculate my taxes.
Guix makes it trivial to add other channels, such as nonguix, providing first-class packages. You can easily add proprietary software to Guix. It's just not part of Guix, because that's not the point of the project. Your "non-mythical" workflows that depend on proprietary workflows are not in any way impeded.
You are projecting zealotry and gatekeeping (both terms with strong negative connotation) onto the project. And I must say that your attitude does nothing to advance your point, however deeply buried in hostile rhetoric it may be.
As to mythical workflows without proprietary software: I'm not using proprietary software. Not on my laptops, my home network, my servers at work. Not because I'm some sort of "zealot", but because I simply have no need for it.
It's really quite odd to observe how worked up you get in response to seeing a community that is content with not using proprietary software.