Usually when someone is unstable and prone to rages people around them tend to walk on eggshells and try to create distance. I think in the situations I have been in when my older sister is in one of her rages is on an instinctive level people address me because they know they cannot address her. Perhaps on a basic instinctive level people freeze because they know that it's the only thing you can do when someone is in a rage. I think that anyone who has tried to stand up to someone in a rage begins to learn that all that does is make the person rage even more. I have helped children work through rages, but with adults it's a lot harder. Sometimes the size of an adult alone can be a factor.