Perhaps they don't have any more courage / discipline / loyalt ect than the average person. But they do have the drive and ambition to dedicate their lives and profession to fighting the bad guys. That is what makes the difference imo. Not that there's anything wrong with becoming a doctor, lawyer, or scientist. Hell, in my opinion thats what the smart people do. Way smarter than me. I believe there are certain people born and bread to do battle. Modern day warriors. These people often end up in military or law enforcement. They couldn't life a full life without that battle. I don't think I could. I don't think less of someone who doesn't want that battle. That's perfectly normal.
I believe that the vast majority of society are very hidden from the real world. Bad people don't scare me. Bad people excite me for the battle which I train for. Regular citizens rarely see evil in it's true form, and when they finally do they usually want nothing to do with it. Sheepdogs (according to the metaphor) have the same capacity for violence as the wolves, except the sheep dog has a deep love for their fellow citizens. They are able to use that capacity for violence to protect those who can't protect themselves. Just as scientist and doctors are rare and specialize in what they do, so does a sheep dog.
For the record I am not trying to make myself sound special or better than anyone else in any way. This is my profession. This is how I live my life. Everyone is different and that's okay.
Saying that you like to get into physical confrontations is perfectly understandable, but that has nothing to do with courage/loyalty/intelligence/discipline, or any other trait other than being excited for physical confrontation. Keep in mind, the "average" person has varying quantities of all these traits, but if you are say a cop, you do not automatically have them, it's just a job and you are just a human, with the same varying quantities.
I'm not trying to downgrade your job or anything, having any actual "career" is respectable and lucky, considering the job market and availability of anything you could call a "career", plus to reach anything in life takes time and effort, so don't take it the wrong way. I just find that quote to be far too "high and mighty" considering the actualities of the job compared to other jobs (in that they are on the same playing field), although you addressed that "high and mighty" thing at the end of your post, to which I say -