Then you are at the wrong place. Phoronix tests distributions as is. Not some highly tweaked performant exotic configuration. That much less practical use for viewing performance. These include 'wildcards' as Unity. That perfectly fine decision.
Yes, we could just test the game in an empty X server with all other TTY's disabled. But who plays games like that?
Not really, it indicates game performance when using Unity. For that point it is valid. If you want benchmarks without Unity, why not benchmark yourself? Btw, we all know that Unity and some other compositing window managers are negatively affecting game performance. Which is kind of a shame since on the other side people are doing their utmost best to fix driver issue's only to be negated by compositing window managers.
You might want to (re?)read post
#10 of this very same thread.