As far as I can tell your only argument against adding a touchscreen is that Apple has previously taken the stance that they would not do it, so that I what I was responding to.

But of course yes, Apple has vaguely and generally declined and their products are flops. Unlike the good old days of the first versions of Mac OSX, the G4 Cube, the iPod HiFi, the flaking-paint Titanium Powerbook, the bendy iPhone 6, or of course Ping, the revolutionary music social network.