Because it's directly at loggerheads with net neutrality. And it's not free. Rhapsody may be paying for data costs. Imagine you are a small startup competing against Rhapsody. Customers will always go for Rhapsody since it doesn't count against data caps. And as a small startup you can't afford to pay required money to carrier and even if you can afford then it's at the mercy of your carrier. Why do you need gatekeepers?