if graphics were a standard, then why are 2d and 8bit games still succeeding? just as many has already said, it's all about that content.
one example of a game failing due to content, yet had very good graphics for the time was Star Wars The Old Republic. This game looked amazing and was one of the reasons why I got it upon release, in addition to KOTOR, however just a few months after release, players completed just about 100% of the game and complained "there just isn't enough to do here".