I greatly enjoy science fiction and fantasy stories that try to examine interactions with other sapient beings whose moral values are extremely different from our own (such as Speaker for the Dead). But these are very far from not having relevance for out own world - they teach us to move outside of our own perspectives and understand worldviews that are far different. That's an intellectually healthy thing for anyone to be able to do.

If a person does want "shallow escapism" with the heroes killing monsters that are straightforwardly monstrous, then there's a fairly easy solution - make the monsters tough but non-sapient. It's having sapient monsters that the heroes define as universally evil, and that the heroes thus kill thoughtlessly, that creates damaging parallels with real life, and damaging thought patterns.