People are fairly simple creatures who are easily tricked because of their addiction to patterns and basic context cues. People want to trust you, like you, not need to kill you. Heck, you could be an asset to their team if you turn out to be someone they can trust, let their guard down around, and learn to lean on.
We see characters like Daryl on The Walking Dead become fan favorites both in and outside of the show while still being kind of dickish.
Have you seen the post-apocalyptic movie A Boy and His Dog1? It was everything a wasteland movie should be and so much more.
Though the message of the movie might be confusing on the surface, the take away wasn’t about the sex, violence, fanatics or even the crazy disparate cultures that came out of the life after the apocalypse. The take away was about the value of the relationship between a boy and his dog.
Animals is a self-published short story by Lauren Shain-Raque that I found on smashwords.com by searching for “apocalypse”. The story follows Dania and Gil through some awkward interactions and deep revelations on the military base they and many others must live on to keep themselves safe from “Animals.”