I think the cinema mode is to ensure that you don't have to take the device off when you switch between a game that's designed to support the Rift and software that does not. With that it mind, it seems like a reasonable compromise. I mean, do you want to have to take the thing off every time you alt-tab to Windows Desktop, or do you want to be 2" from the Windows Desktop?
I think it's two fold. First, you can't just slap VR into existing games. It needs to be considered and implemented deliberately. Second, I don't think the XBox One powerful enough to drive an Oculus Rift. The recommended specs for the Oculus Rift are "NVIDIA GTX 970 or AMD 290, Intel i5-4590" or better. The XBox One doesn't have that CPU power and it certainly doesn't have that GPU power.
