Consider that, for the longest time, it was nearly impossible for folks to drive GVs without frames per second dropping to (low) single digit numbers. It's still a massive hit, way more so than the largest of furballs. FORCING everybody at max settings would cause most to quit driving GVs. End result: YOU have nobody to shoot!
On the other hand, if HTC were to force all to the LOWEST minimum specs, that would also improve FPS if they could just remove most of the trees and bushes from the game. You remember back in AH1 days back before all these trees and stuff? Folks still had fun then! They still had FPS then, too!
It's a toss up between alienating 90% of the GV drivers with lower end PCs (the majority), or dumbing it down and removing all the eyecandy so that everybody's on an even footing.
Personally I think the second option is better.