Had people been armed right there at the start of this jihadi attack, once again, the carnage would not have happened.
Did you see the guy on the motorcycle? He was killed when he jumped onto the truck, fell off and was crushed trying to stop the terrorist.
Brave man.
I think it likely it would have. Scenario: you are standing in the middle of a crowded pedesrian area. Suddenly you see a truck barreling towards you at full speed. Do you (a) get the hell out of the way or (b) go for your gun? If (b) how likely are you to get off an accurate shot that incapacitates the driver?
The driver in this scenario, with surprise and speed on his side, has a huge advantage over even armed people.