The results, without needing to read through everything: optimizations have very few wins and, in spite of expectations, have instances where optimized binaries are slower.
In other words, it's not time. Perhaps it'd be worth revisiting as compilers improve over the next few years.
From the article: "For some of the numerical or cryptographic code there are noticeable gains and it seems to be worth the effort to provide optimized code. This also makes Fedora more attractive to people interested in optimization."