When I look at the offensive force powers (especially move), it seems like a force user with a rating 3 or 4 could cripple or kill another force user easily if he gets initiative, because there is no real defences against the force powers, other than spending your attack on protect.
In the movies, we don't see most of the powers being used against the force user, unless the target allows it, or is distracted or injured. The closest you see is Vader vs. Luke in Empire with Vader throwing things at Luke. But at that point Vader dramatically outclassed Luke.
So am I missing a mechanic somewhere?