Yall in here arguing who is right and who is wrong...and that is a prime example of why the writing failed the game and kinda the show too. Which is the source of all the controversy in the game.
The point of this was supposed to be, nobody is right. But that seems lost on everyone which shows they didn't convey that well at all. I think the show tried to fix that by explaining Abby's motives early on but it didn't seem to work.
From Joel's perspective he was the hero and the fireflies were villains. From Abby's perspective the fireflies were the heroes trying to save everyone and Joel was a villain. From Ellie's perspective she's now the hero and Abby and her crew are the villains. But everybody only sees Abby as a piece of shyt so it all backfired.... again