Problem is, that's exactly how the human brain interprets real-life people, too. You can call it the Monkeysphere or Dunbar's Number, but fact is that people are incapable of conceptualizing random strangers on anything like the same level as familiar people. It's the reason you have more emotional reaction to a package being delayed than you have to a suicide bombing in Afghanistan. It's a limitation of the human brain. Movies and games with collateral casualties reflect the way every single human being actually looks at the world; you just notice it because it's someone else's version of who's important and who isn't instead of your own.