Yes agreed. I mainly referenced law enforcement and security type professions because, due to their very nature, will tend to be "targets" right off the bat. That uniform, more so then the gun, is primarily (imo) what does it.
To this day I still don't like sitting with my back towards a door and tend to always watch people entering or exiting an establishment (when I'm in it of course, I don't drive around randomly watching people lol).
My wife tell me I look at people too much. I guess (I hope) it will change when I eventually retire.