I didn't feel anything about the random guy who said like two lines. I think MC is overthinking it really. Kinda like Shinji from EVA, but less bitchy about it.
That plot device used. Made the world feel a lot more realistic than plastic. The fact that if you kill that many faceless people there is a possibility it would be someone you know that you killed. In a world like that. I can feel for the MC. I can only imagine losing a friend I've spent so much time with. And not only losing them but having been the one that killed them. That's just scary in its own way.