It isn't, but gamers are just a vocal ultra-minority on this industry since at least 15 years now. The leap in graphics is not a game changer, but most people here doesn't play (that's for toys and that's why Nintendo isn't cool), they experience interactive experiences that are supposed to be art.
Why do you think that every time a west developer like Naughty dog or Remedy speak about their products they focus on the graphics or the plot? The same goes for Guerrilla, most of EA, Ubisoft...
Its a differentiating factor. I mean really, can you imagine any kind of long talk about some 2D platformer's gameplay? Those mechanics have been done to death.