Nobody wants 3.4 or 4 inch screens back, and nobody has argued for them. I literally have never seen this once. What I have seen over and over however is that some people want a full-screen device with an iPhone SE/5 (or slightly larger) form factor. Some people like to have a device they can use with one hand. Others don't or don't care, and that's fine – they have those options available. But the fact that the best-selling model had a 6.1" full-screen display while also being the cheapest model in that lineup doesn't prove anything with regard to size when there was no scaled-down full-screen alternative to compare to at a similar price point, and there never has been.