Okay, in that case, yes I do agree there is fragementation. However, I argue being a single OS distributor Apple's move forcing people to move to newer device,

Okay, in that case, yes I do agree there is fragementation. However, I argue being a single OS distributor Apple's move forcing people to move to newer device, SDK and standard helps to achieve the long term goals. When was the last time you ever thought about upgrading to Android officially from your phone's? Well, at least for contract phone I have I can't upgrade unless Motorola supports it and doing custom build is a lot of work and I care about stability. For the iOS I wait a bit before upgrade (usually 2-3 months after each new release of iOS).