Nominally, RPGs are for the broad experience, the gameplay, the fun. Stories aren't always creative, or original, things like that. Those are reserved for the action/adventure, usually, with a parallel focus (for some) on gameplay instead. For some examples, we know the story (Zelda, Mario, Batman, anything with any military ever, Lego), so it's all about how we play. For others, it's about what we're playing (Prototype, inFamous, Assassins creed). We know the JRPG storyline by now--a bunch of teens with various flavors of exposition going off to kill the current Evilest Badass with the Biggest Sword.