And sometimes they take everyone back into the storeroom and shoot the compliant sheep, one-by-one.
Yes, times such as those are why I said “almost never” instead of “absolutely never”. They happen, but they’re still incredibly rare.
Overwhelmingly, if you want to get out of a robbery in one piece, you surrender your valuables without a fight. Almost every time you’ll be fine, because almost every actual “robber” is out for money - not homicide charges. You can get away with a robbery a lot easier than you can get away with killing people for no reason. If nothing else, you get pursued a lot less vigorously over chump change rather than spilled blood.
The incredibly rare cases like the one you cite typically aren’t about money - notice that the perpetrator in that incident was an employee of the restaurant and attacked his coworkers. How much do you want to bet this was a disgruntled employee “going postal”? And we’ve already been over the whole mental health issue already in this thread.
Not sure why you picked this weapon to pick on. TV perhaps? The 1911 is an excellent weapon and, indeed, nothing says STOP!!! like a .45.
I wasn’t critiquing the quality of any particular firearm, I was using an example of a commonly owned and commonly romanticized one that has a very powerful presence in American gun culture.
You yourself seem to illustrate the odd affection many people have for the weapon. As I’m sure you’re aware, it’s a military handgun that saw use in both World Wars, and many millions of them were made and floated around afterwards. It’s a cheap and simple weapon, it’s iconic and immediately recognizeable, and it’s easily copied and cloned. Consequently, it has ended up as the AK-47 of handguns - it is a symbol as much as it is a killing tool.
And for your infomation, I don’t watch television. 
Law doesn’t factor into the equation. Conflict escalation is essentially anything you do which makes a conflict more difficult to resolve peacefully. Conflict de-escalation, or conflict resolution, is the opposite - it is taking steps to diffuse tensions and reach an outcome which involves the least harm.
If a person robs you at gunpoint, the quickest and most reliable way to resolve the conflict is to surrender your valuables without antagonizing the attacker. In all but the most absurdly rare situations, the thief will flee with the valuables and the conflict will have ended.
If you’re feeling brave and confident, you can try to talk the person down, employing reason and empathy to convince them to change their course of action. This is more dangerous, as accidentally provoking the attacker with your words can effectively escalate the conflict further, but if you are successful it can have a more lasting and profound impact on the attacker. Of course, it helps to have training in conflict resolution before you consider such action, because it is inherently more dangerous than simple compliance. Again, it is always fastest and safest to simply surrender your valuables without provocation.
Or you can draw a weapon, which by definition instantly escalates the conflict. You’ve just raised the stakes. Before, the robber felt like they were in control and were getting what they wanted - their motivation for starting to shoot was rather low, because once again, they want money, not homicide charges.
Now the robber feels like their life is on the line - they see someone pulling a gun, meaning their life is in immediate danger and they need to react instantly without time for a reasoned decision. They are forced to make a split second choice - fight or flight. Surprise surprise, it turns out that desperate, nervous people who have guns in their hands tend to take their chances shooting rather than running when forced to choose how to save their own lives.
Sometimes no one shoots, and it turns into a standoff. But that’s still far worse than just giving the asshole your wallet and letting the police sort him out later. Sure, you keep your wallet, but now it’s all but certain that bullets are going to fly unless someone de-escalates the situation.
If you want to avoid a firefight at this point, you need to come to some sort of agreement - meaning you need to talk them down. That’s going to be a lot harder now that they’re swimming in adrenaline and millimeters from pulling that trigger. And if you really wanted to talk them down, you should have done it before you pulled a gun.
No, drawing a weapon on someone really only ever has one real purpose - attempting to kill them. Even if you only intend to “threaten” them, you’re still threatening to kill them. The only reasonable expectation you can have in that situation is starting a fight to the death.
