"Their network?" What does that even mean? How is the fact that we have 1) The internet, and 2) Tablets with Wifi made by Apple, make it Apple's network?

The iOS devices are no more a "network" than are Macs are a network, or Android devices are a network. They are pieces of hardware.

Lets take the foremost example: Kindle. Apple does not create, distribute, filter, or store the content for Kindle. I purchase Kindle books, and I view my purchases on a variety of devices. When I choose to download a book to my Kindle for reading, pray tell where does any of this touches an Apple asset? I own my iPad. I pay for my internet connection. Amazon stores my books. I download them from Amazon to my iPad.

What possible justification does Apple have for demanding a cut of the books which I purchase from Amazon? How can they demand that Amazon not provide a link to purchase more books on a website that Apple has absolutely no fiscal interest in? It's none of their damn business!