1. See something you want to play with, play with it.
2. Bad with math? Play AoS. No pesky math required.
3. Hate people talking about a tournament scene, or net lists? Play AoS, there are no net lists and unlikely to be a tournament scene.
4. Pretre said update Brets. (Although, that's not the same as releasing a Bret book, since the update can only be played with AoS)
5. Monsters get weaker as they take wounds, really good idea.