I am designed to kill. My body is the product of thousands and thousands of years of humans killing things to survive.
The fact that I've never killed anything is a freakish abnormality. It's only possible because I was born in this recent time period in this small sector of humanity that can hire other people to kill things. Rebelling against my natural purpose like this is actually a massive problem. When I get stressed my body gets flooded with chemicals that are great for killing, but terrible for passing exams.
Games are about solving hypothetical problems, and the most common hypothetical situation is "What if you had to kill things to survive?" There's a lot of grumbling about this. People suggest opposing, peaceful hypothetical situations, like "What if you had to navigate emotional turmoil to survive?" or "What if you had to create stuff to survive?" There's a general feeling that we'll slowly outgrow our murder simulators, and move to pacifist games.
The problem is, I already live in a world where I have to navigate emotions and create things to survive. The point of a hypothetical situation is to explore something you can't in real life. I'm a weak, creative guy living in a civilized world that prizes pacifism and creation. That means the best possible hypothetical situation is to be a thug in a brutish dark age that prizes violence and destruction.
It helps that most of human history was a lot like that. Learn from history or be doomed to repeat it, right? Imagining myself killing a dragon, or doing it on a screen, doesn't bring me much closer to the billions of humans that had to kill things. But I can't imagine any hypothetical situation more compelling, more useful, and harder to experience in real life than killing for survival.