Because she trades tanking for a butt ton of mobility in an ult and has a far more reliable kit. But, unfortunately, you have to keep in mind that team fights DO matter. Once the game hits the point of everyone flocking together and waiting to see which person done effs up first, Graves either works with the team or risks being picked off. I am sad to say that the latter is far more often the case in my experience.
Don't get me wrong, I really do not feel strongly against or for Graves. He's just a pain to deal with. But I do not know if being a pain to deal with is what makes a champion broken. A lot of champions are a pain. All of them, in fact.
You're right. He has an incredible burst. But if they WERE to do something to balance him, I would think that the best thing to do would be to make his Q (his gunpowder boom boom thing) have the same delay if it hits a wall as it does when it doesn't. Unless that's changed recently, I don't know, I so rarely see him.
[slayer-pantheon-rainbows]