1. The concept is ludicrous. No matter how deranged people get in the future, they'll never think it's cool to watch 12-year-olds claw each others' eyes out for entertainment value. And they certainly wouldn't think it's cool to watch 16-year-olds massacre 12-year-olds. If the competition's minimum age was 16 the story would have been less forcefully melodramatic and more believable.
2. "Katniss" is a stupid name. And now these books are probably inspiring others to name their daughters that, making our world more annoying and unlivable.
3. The writing is distractingly choppy, with horrible transitions between scenes.
4. Its biggest calling card is that it's "better than Twilight." So is dog excrement.
5. Too many people like it.