That's only a problem if your FOV is too small. With a large enough FOV and a light display there's no reason why eye and head movements shouldn't work exactly as they do in real life. The Oculus Rift has twice the angular field of view of the SU2000 in both dimensions, for 4x the subtended angular area.

Edit: Oh I see, your complaint is about using the head tracking to control a game, e.g. by pointing a gun. Yes, I think that's a bad idea. Head tracking should only control the camera. All game interaction should happen through a controller. A motion controller like the Razer Hydra would probably work well for this.

if you move your head for any reason you can't maintain focus on objects

Again, only true for crappy hardware. With a good enough display, 120 FPS, and low latency, there's no reason why tracking moving objects shouldn't work just fine.

I think a lot of people got disillusioned with VR because there's a lot of crappy hardware out there. Even the expensive stuff is crap. I tried Canon's augmented reality system at SIGGRAPH last year and the latency and FOV were awful, despite the $120,000 cost. But it doesn't have to be that way, and the Oculus Rift is the proof.