I liked the ending, it made me evaluate my own views and opinions, I've always talked a good game when dealing with hypothetical situations ("needs of the many...", "the species is more important...", etc) but when the concept of Ellie's death got brought up I immediately started thinking along the lines of there has to be another immune or that eventually the mutation will occur again, I knew that those were less beneficial, even unlikely, solutions (this point really hit home when Joel used the same excuses to trick Ellie). A part of me didn't want to sacrifice Ellie for the greater good against my better judgement. That is something that I know about myself now, that such a decision would not be so simple for me to make.
Claiming this this game "may stand the test of time as one of the first games that had the guts to go truly and utterly dark." doesn't sit right with me. First thing that came to mind when I seen this ending was the bad end of Persona4 (not saying it was the first).
You spend the whole game being a good guy (ideally), saving the town with no desire for compensation and forging bonds with the people of the town. From the moment I met (spoilers, I guess) Adachi, He seemed suspicious, he didn't do anything obvious at the beginning, hell you didn't even know there was an issue at that point, but something seemed off and as the game went on his auspiciousness became almost ludicrously apparent.
But then the mess with Namatame, happened. That took me by surprise (I never talked to him at the river bank much so perhaps it was telegraphed but I missed it at least). Then the Nanako event happens, I was legitimately livid, I was consumed by my anger and fear by what had just transpired and the game gave me someone to blame, someone who up until this point I never would has suspected. If you give in to that negativity you basically kill a man based solely on your emotion at the time, the rest of the game skips past all the fun wacky misadventures of the "post resolution" phase and you sit in silence while feeling so awkward that you question your actions. I felt this was far more impact-full than the the last of us ending because I made the decision, I gave into my weakness, I failed, I got that bad end and I had no one else to blame. I suspected the actual villain, but when I was forced into a state of mental duress I through an innocent man who didn't make sense under the buss (nicer than saying I killed him) to make my self feel better due to some false sense of justice, justice I knew was fake but accepted because it was better than feeling as powerless as I did when despite my efforts Nanako died.
Curse these fleshy emotions, or perhaps I just get too easily immersed.
(super irrelevant: Captcha didn't accept my description of Subaru as a "wheel box")