I dislike Apple, but TBH, this is probably because the next gen iPhone will use a different screen. They never had to cut screen orders because they kept using the same small display on each iteration. It also makes sense to try to get an even distribution of your parts among suppliers so that you don't get so dependent on the capacity of one supplier, that they can bend you over with contractual price hikes (Samsung). Although Samsung's price hike was entirely deserved on Apple's part, from a business perspective, you don't want to get into that situation again.
Also, year over year, they are selling more iPhones. While they don't break down which models are being sold, they are still selling more. Even with the used market created by people selling their last-gen phones, Apple is still selling new 4Ss.
That said, I still prefer my SGS3. I wonder though, how much innovation would Android phones see without everyone chasing Apple's popularity? I may not prefer Apple phones, but I can certainly appreciate that they are definitely driving competition, and phones are getting much more advanced because of them.