It's not. However, with this product it is clear that the issue of what is good for the business is the primary motivation, and the question of what is good for the game is a much lesser consideration (if it is being considered at all).
D&D is (or was) a collaborative game. Game balance is about trying to ensuring that nobody is overshadowed by anybody else, because that's not fun (and wasn't eliminating the not-fun one of the key parts of the 4e rollout?).
The structure of this product means that the player who spends the most will have the best character, and probably not just slightly. They're sacrificing game balance for money, and that's why this is not a good thing.