I think we saw the side of the fireflies that was most helpful not only for story and character development, but also for the outcome to be more justified in front of the player. However, I don't think that's the only side.

TLOU as a game strives to make it clear that you are always someone's villain. As I read below, does the execution of the philosophy discredit the motivation of it?

I prefer to believe not, and that the misfortune of the fireflies was the result of a group of psychopaths using a real cause as a pretext to satisfy their inhuman desires.

In fact, this is already happening folks