Having said this, Apple can do as they please. They control the hardware, the OS, the App Store, and the user accounts. The same was true of Twitter who effectively squeezed access to their API until one or two desktop clients remained.
The only two ways out of this is to legislate a lower rate (through campaigns such as these), or to create a competing platform that lowers costs for its users. Imagine if Spotify offered a lower rate for Android users... Wouldn't that send a very clear message to Apple?