Most people do not have a problem with Joel dieing but with the deliverance,the wrongdoings of Joel in the first game had build up and made you feel for the character that did it while the fireflies were never a perfect organisation and had testsubjects before that failed to deliver a cure(Ellie was not unique), so there was a deeper connection that made his choices more meaningfull for the player,and surely after the whole father/daughter buildup.
This absolutely had almost no buildup and there are so many coincidences and out of character things happening to even get to the point of the brutality that comes too early for letting it feel justified for the story,it felt like the game wanted to cover major plotpoints without much care how to get to them.At the end it was a simple revenge story written badly,even Stephen King his worst books stand miles above what this was imo.
I do not applaud this just being shocking and daring while it comes of as uninspiring and lazy,the only positive about the writing for me personally is that while i disliked most characters by the end i finally started to feel something for Abby and i'm happy she got away cause what would be left without that? Just the terrible Ellie and nothing to return to.