Why is Apple discontinuing the iPad 4 but continuing to ship the iPad 2?

Imho the most important point is still missing: with the iPad 2 only being 100 dollar cheaper in comparism with iPad Air, you teach the consumer to take the newer, more expensive product. Would this be an iPad 4 the consumer would easily take the 100-dollar-less version. Now you'll compare iPad 2 and 5 and