pkgconfig files are used to standardize stuff across distros and make developers use them in their build systems. Therefore those should generally be handled upstream and patches send there unless it's a minor fix like supporting libsuffix not doing so results in developers using those pkgconfig files and shipping their build system thinking every distro includes them this already happened for dev-cpp/tbb where debian thought it's a good idea to ship it and apps using tbb compile or not depending on your distro
What do you expect with a upstream like NVidia? I support the idea of shipping pkg-config files in the package to continue keeping the binary-only package isolated, but yet, usable.
I wrote an email :D
