One of the main differentiators of price for Apple products is the disk size -- in fact, for iPads and iPods, its the main differentiator. They want to push to

One of the main differentiators of price for Apple products is the disk size -- in fact, for iPads and iPods, its the main differentiator. They want to push to all of your devices, because they want you to use up your storage and pay the $100 to $300 markup between model A and model B. If everything was accessible from the web and it used smart caching like spotify or google, there would be much less need for bigger hard drives.