It's really not about the phones and their size (though it does play a part), it's mostly about the previous models performing just as well as the newer models. Apple makes the iPad thinner and sure boosts the CPU and maybe increase the RAM, but overall it's not that much of a boost over the previous model. If it can run iOS just as well and smoothly as the previous iPad and run the apps just as well, why bother spending money on something that'll replace something that is only a year old? Why wife still uses her iPad 2 and it runs iOS8 pretty smoothly (and that's several generations ago). I find it just as usable as my daughter's iPad mini 2nd gen. Apple should only release newer models if they make significant changes to it. Now the latest iPad Air does have more memory, a newer CPU and finally touch ID, however people bought last years model so financially it wouldn't make sense to upgrade again.