i'm not sure what that has to do with the argument

(curious, though: does the Fedora project even have an equivalent to universe? I also thought that OBS didn't have security updates just like the AUR doesn't.)

No, it's the same with every distro.
Distro maintainers CAN'T support repos containing non-free packages with security fixes.
Because they can't fix security issues in the code.
Because the code is not free for them to edit.

This entire criticism just shows a lack of understanding of how distros work, and what security updates are.