Yes, but Applein the 2000's was notorious to kill products that still make profits for the sake of keeping the product line clean and lean, and not have consumer confused over which product to choose.
Ok, but look at something like the iPod. That strategy makes sense as it is a relatively low cost product. Cost was part of the reason Mac's never got high market penetration. The iPhone is very expensive, especially compared with the competition. Offering old models at a lower cost allows people with less money to buy into the ecosystem. This is important when you have a product like the Watch that requires an iPhone first.
