"This size isn’t sufficient to create great tablet apps in our opinion," Jobs said during a 2012 Apple earnings call, referring to competitors debuting 7-inch tablets.
"Well, one could increase the resolution of the display to make up for some of the difference. It is meaningless, unless your tablet also includes sandpaper, so that the user can sand down their fingers to around one quarter of the present size."
"Apple’s done extensive user-testing on touch interfaces over many years, and we really understand this stuff, " Jobs continued. "There are clear limits of how close you can physically place elements on a touch screen before users cannot reliably tap, flick or pinch them. This is one of the key reasons we think the 10-inch screen size is the minimum size required to create great tablet apps."
Two years later, Apple announced the 7.9-inch iPad Mini.