Doesn't the PS3's Cell processor do more than this, and it came out years ago?
It obviously wasn't the goal of their article to isolate to performance issues to help find the problems.
It WAS the goal to install each version separately and test different areas of the performance.
And the fact is that in most areas Linux performance (not just Ubuntu, it's not like they do anything others don't) is going down. This isn't the only benchmark that shows it. Whether it be in new kernel features like CFS, the file system, i/o changes, bad drivers, gcc changes, gtk issues and so on. Linux in general isn't getting any faster, and this is a huge problem that should be looked into by ALLLL distros. Ubuntu, for example, could put an entire (6 month) release cycle, or even 2 release cycles (Apple is doing this with the next version of Mac OS) into performance optimizations but it wouldn't do a lot of good because they would have to be looking into Gnome, GTK, and all the other applications that go into it.
Even for me I have noticed issues, windows resize much slower in the last few years, I can't even use NVIDIA drivers with Firefox as the Ajax performance goes to hell, even writing to USB flash drives is noticeably slower than windows. And it's unfortunate because Linux is all I want to use.
Real Users find the one combination of bizarre input values that shuts down the system for days.