For me, personally, graphics are not the be-all end-all when it comes to videogames. Of course if I play something that looks beautiful and amazing, I'm going to appreciate the graphics and probably take a lot of screenshots and admire the game... but if the gameplay is bad, the story is boring, or there isn't much to do... well, I'm going to close it. I also play a lot of older games, and also pixel games, and find them more enjoyable than most realistic-looking games.
With Borderlands, I could barely play it because of the stylised graphics. I found it difficult to differentiate between the landscape and the enemies and I found it hard to play because of that. But also, as you say, if the Last of Us was created with Borderlands graphics, not only would it look terrible, the story most certainly would not have the same impact.
RE: Graphics are important, but to what extent? - [ENG/ESP]