In the entire forked-up mess of the unix tree, there was only one thing that anybody & everybody cared about - source compatibilty. C99, POSIX, SuS v3, so many ways you could ensure that your code would compile everywhere, with whatever compiler was popular that week. For a good part of 4 years, I worked on portable.net, which had a support/ directory full of ifdefs and a configure script full of AC_DEFINEs. It worked nearly everywhere too.
Binary compatibility never took off because there is so little stuff that can be shared between binary platforms. Sure, the same file could run on multiple archs, but in reality that is no different from a zip file with six binaries in them. Indeed, it needed someone to build 'em all in one place to actually end up with one of these. Which is actually more effort than actually letting each distro arch-maintainer do a build whenever they please. OS X build tools ship with the right cross-compilers in XCode and they have more of a monoculture in library versions, looking backwards.
Attempting this in a world where even an x86 binary wouldn't work on all x86-linux-pc boxes (static linking, yeah...yeah), is somehow a solution with no real problem attached. Unless you can make the default build-package workflow do this automatically, this simple step means a hell of a lot of work for the guy doing the build.
And that's just the problems with getting a universal binary. Further problems await as you try to run the created binaries ... I like the idea and the fact that the guy is talking with his patches. But colour me uninterested in this particular problem he's trying to solve. If he manages to convince me that it's a real advantage over 4 binaries that I pick & choose to download, hell ... I'll change my opinion so quickly, it'll leave you spinning.