I think there is a cycle - or so it seems - that is maybe coming into play?
People who are "above average" apprehensive or fearful - of things that may happen to them - people who might break into their houses, people who might do something to them in their yards, people who might steal their cars, whatever, who purchase dogs for their visual deterrent and who activate the fear/anxiety in their dogs when these things happen (EEEK! A person! the person thinks), causing the dogs to react - EEEK! My person is scared, I should be too! - and going round and round.
I say this as a generally neurotic person who has developed much more confidence and assertiveness after having a fear aggressive, dominant dog who I had to protect because though he was afraid, he really did think giving someone the business would be fun.
After getting the fear aggression part taken care of, he became quite the pushy, ready to engage kind of dog, staring people down, having that Mendlebaum "It's Go Time" attitude. If I showed any kind of fear or nervousness, that dog was on and that just isn't good. So I controlled my dog by controlling myself.
Then either one of us was ready to give someone the business.
Unfortunately I have not been able to cap fear this w/my dog reactive dog so he's a prisoner to my emotions - working on it!