It wouldn't work as well though. Imagine you want to turn your head...
With the wiimote standing there, and you wearing the glasses, the two leds would get closer together, so it would know that you had turned (it could work out that you hadn't moved further away as the intensity is constant).
With the sensor bar standing, and the wiimote strapped to your head, when you turn, the wiimote will not be able to detect the sensor bar anymore as it only has a 45degree angle of detection on each side...