We don't use patchelf for any official package definition. We have a package for patchelf, but it's only really useful when you have pre-built binaries that you can't rebuild from source.
The main guix monorepo may set that hard requirement the everything just be built from source, but if you want to run closed source software than your only two options are make a fake FHS or use patchelf. Both methods have pros and cons. Only patchelf makes the result work well with other closed source programs.
While from a philosophical point of view guix is pure, real world usage often needs closed source software.
While from a philosophical point of view guix is pure, real world usage often needs closed source software.