At its core, "The Last of Us", as a franchise, lives or dies by its characters. The first game is still regarded as a masterpiece, by many, not because of its gameplay or graphics, but because of the strength of its character-driven narrative, using phenomenal character development and relationship-building to elevate a fairly standard post-apocalypse narrative into an experience that resonated very deeply with a lot of players.
Its sequel, sadly, completely fails in this regard. Character takes a backseat to plot, and relationships are pushed aside for experiences in a meta-focused narrative that seems more concerned with shock-value for players than world-building for the characters living in this fictional world. Not all game stories have to be fun and uplifting (I write as an avid fan of the "Pathologic" series), but if people go into a game expecting to follow alongside beloved characters as they struggle through adversity, only to be surprised with sophomoric torture porn that reduces many of those same characters to mere tropes...you can certainly begin to understand why people are reacting so violently to this game's release. Maybe this game could've worked as a side-story or an entirely different IP altogether, but as "The Last of Us Part 2"...it's an utter failure.