Response to "snipers" by Andrew Malek

In the video Malek provided the narrator goes on and on talking about how concentrated the sniper needs to be. How they can't dwell on the target that they have hit, they need to move on. But what happens when the sniper isn't mentally tough enough. I feel that "The Angled City" provides us with some insight to this matter. When N's realizes how close he really is to the people something changes mentally for him. We can see how the mental change or mental instability makes him a much worse sniper. He barely is able to kill people when he used to be able to joke and make games about killing them. His human side is too exposed. This is the exact mindset that the sniper video said that you cannot have. So does this video tell you you have to be a robot and not a human?