The work required to fix packages affected by this disadvantage
(potentially) far outweighs any advantage
Bollocks .. just sed/perl oneliner which will add BuildRequires: pkgconfig if in package is used any "BuildRequires: pkgconfig(<foo>) and remove from rpm dependencies autogenerator add "Requires: pkgconfig" if package has any on the list any pkgconfig file -> rebuild all affected packages.
It should take ~1h for someone with proven packager priviledges.