It's one thing for the aliens to play on negative Earth stereotypes (the commentary I was expecting and looking for), and it's another thing when the POV characters do. It's Carl's first person POV depicting the people and events using that language, not the aliens'. And it's Princess Donut telling him to kill because she's "disgusting." He wants to help/team up with her, but the sarcasm of "Yeah, that'll be a no" is basically the entire argument it takes for him to do a murder instead.
Because if the author originally intended this to be about how horrible the aliens are, then the MC shouldn't be the one thinking these horrible things. Full stop. But the author is the one who chose to do a first person narrative. He failed to describe people in a way that doesn't put the words and feelings in his MC's head.
