There are places & times that Open Carry is easier or better than Concealed Carry.
BUT,,,,,,, you have to be well aware of where you are,, who's around you, and place your body in a position where a thug couldn't snatch it.
And of course,, CC is also a good idea for many other places or reasons.
I guess the best way to describe it; "It all depends,,,,!"
But that guy in the video was NOT aware,, nor did he protect his gun by keeping himself in a position to prevent it from being snatched. Add in he was quite stupid to follow the guys out of the store & trying to "reason" with them.
As for being a "target" if a thug is sizing up a place to rob or whatever,, there are a those who may NOT try anything fearing return fire. Or,, if the thug looks at the person,, and decides,, "That guy is my first target" may well be distracted from his initial reasoning for wanting to attack or rob a place or person. And if the OC guy is aware of their surroundings & the people around him,,, they will often realize that there may be a potential threat,, and already be taking slight but firm offensive maneuvers to prevent being the "first target."
Situational Awareness is still one of the best defenses against an attack. Another one is NOT being in places where crime is more common or criminals are more likely to be around.
In short,, no one method or whatever works for everybody all the time. Too many variables.