Apple takes a bite of every cherry
It wasn't that long ago that Apple (and many others) were decrying Microsoft's corporate greed and accusing them of being a marketing company that sold some software. Well Apple's insistance on a 'closed shop' approach to app development and retaining a percentage of all sales through apps on their devices smacks of exactly the same thing. In fact Apple's world is so closed that Android may still steal their thunder whilst their not looking.
(Oh No, I mentioned Apple, Android and Steal in the same sentence, maybe Jobs is still lurking in my subconcious)