There are loads of sociopolitical, racial, class and future-planet situations that really interest me, but I'm not really interested in making a film about them in a film that feels like reality because people view that in a different way. I like using science fiction to talk about subjects through the veneer of science fiction.
I had artists that refused to work on Chappie if they were working on a design that actually said Denel on the side of the thing. But anyway, it's the blurring of fiction and reality that was appealing and I certainly did not want them to be in the movie and not be themselves.
This whole notion that the robot has to declare nuclear war is one part of the discussion, but it may not be reality. Reality is, maybe it can empathize to a far greater degree than we can and experience a way wider range of emotions. So, why not have a robot that can do that?