Apple wants to be a walled garden. Can't be a walled garden without walls: their self-interest and marketing direction lies elsewhere. Also, in the case of the

Apple wants to be a walled garden. Can't be a walled garden without walls: their self-interest and marketing direction lies elsewhere. Also, in the case of the iPhone, hardware is the product, and in the case of the app store, the devs and apps are the product (some of the time, anyway).