I just wanted to bounce an idea I have here.
It seems to me that in our mostly safe society humans are no longer exposed to violence on a regular basis. (that's a good thing)
 But it seems that as a result people frequently just fall apart if violence comes their way. The gears in their brain just lock up as something is happening that isn't possible. Or isn't supposed to be possible. Or doesn't happen to nice people. Or doesn't happen............or doesn't happen................. I think you get the idea.
Instead of the brain going "RUN!!!" Or "FIGHT FOR YOUR LIFE!!"   the brain goes "Why? "  And the person folds up on the ground and all they can manage to say is "Please stop."

It is my belief this is a result of humans no longer being under frequent danger.

Thoughts?

The 'Freeze' reaction you describe is often a result of cognitive dissonance.  It results from an inability to reconcile the observed reality with preconceived notions, thereby stalling the OODA (Observe-Orient-Decide-Act) loop in the orient phase.

There is a relatively simple solution: recognize that violence is real, and prepare for it, with increasing amounts of pressure in your training.  It's not a guarantee that you won't freeze, but you can systematically condition yourself to be more likely to perform under stress.

I can't seem to find it right now, but there was a study done in animals that postulated adrenaline could also serve a third function:  preparing animals to die.

One of the side effects of adrenaline is that the animal (us humans included) feels less pain/discomfort.  I'm sure that everyone who has dealt with fight or flight can attest that they didn't feel the pain until after the fight, or they didn't feel tired until after they reached their car in the parking lot after they were chased by the chainsaw wielding maniac from the haunted hayride.  Adrenaline is a heck of a drug.

I used to wonder why the rabbit didn't fight to the end when the dog caught it and was just carrying it around in it's mouth.  Adrenaline had set in and the rabbit was just awaiting it's fate.  I've also seen it in some of the vets I've dealt with who have PTSD.  I've seen them in positions that are making them stress out, but they just "zero out."  A lot of people think that they are just apathetic or ignoring the situation, but if you observe them they have a heavy pulse and may be sweating some.  They have an adrenaline rush and can't function.  Often they will tell you that they are stressing out and can't do anything.  (I've noted that a lot of my coworkers will just talk over them or dismiss them, which ticks me off.)

So, the majority of the populace tends to be "soft."  The majority of us on this forum know that in order to win a fight, you have to have the mindset that you are going to win the fight.  But many citizens have no real fight experience or no military background...  When Big Bad Jim goes to beat up on Little Mary Meek, Little Mary thinks that it's all over because on TV the big dude always beats up the little person.  Mary's adrenaline is going to help her die.  But when Big Bad Jim tries to beat up Big Bertha?  Well, Big Bertha ain't got no time for that!  She has a lot of ire and anger and she's going to teach this overgrown snot nosed brat a thing or two!  Big Bertha's adrenaline is going to help her fight, and her mindset isn't one inclined to back down.  Now Bertha's wooden spoon isn't going to do much harm to Big Bad Jim, but he's rattled all the same so his adrenaline is going to help him flee.   His mindset was that Bertha was an easy target, just like Mary.  But when Bertha fought back, Jim went from "winner" to "looser" really quick.

I'm going to keep looking for this study.  My Google-Fu is weak.  But I'm sure I have a copy of it in one of my folders from my Academy.

Most people are unaccustomed to and unprepared for a full adrenal response.

A normal person's normal day is spent in a semi-conscious haze.  Even inter-personal interactions are usually done mostly on autopilot.  Most of our responses are pulling from cache (unconscious competence) rather than forcing actual thought.

A life threatening violent encounter forces people out of that haze into the immediate.  The physiological and psychological impact of the adrenaline dump can cause people who have never experienced it to freeze up because they are hit with a sensory overload.  The brain goes a mile a second, there is no muscle memory to fall back on with the untrained, and so they default to doing nothing because the conscious brain can't process all of the options and all of the stimuli it's being fed.  It's not a panic response it's vapor lock.  Fleeing or fighting are the actual initiation of the A part of the OODA loop.