Maybe our mind is deliberately trying to stop us from controlling our dreams. Whenever I go lucid there is ALWAYS some kind of DC around that just stares at me. Dream spinning usually works to get away from them, it's like you go to a different part of the subconcious and your being searched for. I remember having a lucid dream where I was constantly being chased, lost lucidity on one of the dream-spins though so I didn't find out what happened.