In addition to this I think an inherent problem with occulus rift and similar technology is that as humans in the real world our vision is connected with our body. When we move our head, focus and so on we also use the rest of our body. A visual experience is not just visual but a full sensory experience with visual focus. Occulus rift, then, for example, only works with your eyes and so gives you a disconnected experience.

The VR technology tries to eliminate any real world point of reference which makes us use reference points inside the VR which, I believe, is one reason the experience for us gets disconnected.

The most common symptom of this is that you get nauseous. My guess is that the (sensory) disconnected experience makes us lose balance.

What would solve this problem, I think, is to make the VR work with the whole body. So wearing a suit with goggles and standing on a plate that moves as you move which gets translated to in-game movement.