One more thing that Apple does differently is competing with their own older products.
Comparing the new macbook to the old one, iPhone5 to iPhone4S make an huge army of Apple devices owners want to upgrade, clearly seeing the value in obvious improvements, wanting to rise to a new image level and stay on the edge of technology.
What do other manufacturers do? They hope to keep selling older devices and keep finding some mythical new audience for the more recent ones. Competing with previous versions seems too bold for them.
Huge assortment could be a good strategy for small retail. But not for selling 500$+ devices obviously.