How many of you can keep your cool and stay perfectly rational in a sudden life and death emergency? Knowing the exact right thing to say and do?
Some people can, especially if they've been trained on what to do in such situations until it's automatic. But the vast majority of people can't. It's a shame, but that's just how it is. I've seen people fall apart under situations that I didn't even see as dangerous. Normal people who function perfectly well in everyday situations, unable to handle something slightly different and (to them) scary.
How scary is an unwanted encounter with an armed, aggressive gang member who you realize can kill you and most likely get away with it? Knowing that even if you survive, you're going to be poorer because he's allowed to rob you at gunpoint. Isn't that scary enough to make most people do unwise things?
If your criticism of people who get murdered by cops is that "They were acting stupid, or they wouldn't have been killed" I guess if a grizzly bear suddenly attacks you while you're minding your own business taking your trash out at night, you'll act the exact right way to defuse the situation so you can both survive.
If not, shut up. You're just being a stupid copsucker (but I repeat myself).