MS is not doing anything wrong here. You can't compare console to PCs and PCs take up more resources to compute compared to consoles.
I am actually surprised that they are running the games on PCs. But maybe the architecture is so similar to PC it doesn't make much difference to them.
Either way just because the PCs in E3 are using Titan GPUs doesn't mean the graphics will suddenly start looking better. At best the frame rate will end up being a little better. With what the OS running in the background, they might have tried to be on the safer side with an Nvidia (?) titan gpu.
Weird that they went for Nvidia though.







