When the iPhone was released, Steve Jobs was asked if outside developers were going to be able to produce apps for it. He replied that there was no need, that developers could produce HTML5 web apps and not need to access the phone.
Primarily as I recall, he attributed it to the cell phone networks worrying about their networks security if outside apps could interact with their networks.
Was he speaking the truth, or vamping until they could finish the developer tools and open the App Store? He has a history of saying Apple had no intention of entering a market because it was not good for the customer, only to do so later.
Now, the Apple App store and development tools are good money earners for Apple. And they want to sweeten the deal for themselves by demanding apps can only have in-app-store purchasing where Apple then lays claim to 30% of the revenue.
Not a big deal for game makers selling virtual weapons, but for Amazon and others selling books, the book sellers do not have 30% of margin to give away. They would have to raise the prices to cover Apple's tax. Meanwhile, Amazon could sell a book for less on Android tablets since Google does not charge that kind of premium.
Now Amazon has gotten around the program by, wait for it, building a Kindle Reader in HTML5 that seems at first blush to be as good as the IOS Kindle app. Readers can even save their books to the local machine and read them when not connected to the web.
Amazon took Apple's advice from 2007 and nipped Apple's greed painfully.