The the choice of city was as subtle as a sledgehammer.

And no doubt that there are people really this vile, but there are no important human characters completely on the aliens' side. Humans can cause cruelty and misery but also are capable of acts of great compassion and caring. It's the paradoxical nature that both are 'human nature'.

I missed that sense that humans have redeeming qualities. Even when the protagonist acts heroically it's because he was driven by desperation more than altruism. Yes, he grows beyond some of his prejudices, but he acts mainly in self-interest, until the end at least.