I think the idea is.
Better to kill em at the outset than to let em die of starvation because you can't really afford to feed em all. Sorry, author, I gather you didn't mean this to become a forum for talking about that.
I enjoyed the art a lot. I'll have to go back and rewatch and check out that artist you mentioned; that mural looked really interesting. Music very chill and set the mood nicely. Not sure that I agree with the lyrics, but probably they'd be pretty pissed and they can't really lash out except in words, so maybe. Or is the idea that they're just existing and don't really have a conception of nice and mean, so they'd just say whatever pithy remarks occurred to them? I like that meaning, it seems to fit the movie.