I don't really understand the question. The fglrx driver is developed by a team of AMD employees, while the open source driver is developed by a team of developers who mostly do *not* work for AMD. The two drivers also have completely different target markets and different code sharing objectives. The open source driver shares code with other open source drivers (eg Intel, Nouveau, llvmpipe etc..) while the fglrx driver shares code with other AMD proprietary drivers.
And we all share the pain for buggy or incomplete drivers