The apps are mostly compatible (look at the number of straight ported iOS games on the MAS for confirmation here) with no UI rework done. The games ported from

The apps are mostly compatible (look at the number of straight ported iOS games on the MAS for confirmation here) with no UI rework done. The games ported from iOS and Launcher, maybe, but most apps are not "mostly compatible". A few examples: Safari, Mail, Photoshop, iTunes, iPhoto, Pages, Numbers, Garageband, etc. Also everything third party: Chrome, Photoshop, Word, Evernote, etc etc... Non of those are designed with touch interaction in mind. This shows in the layout of the menus, toolbars and buttons, and is even more evident in the size of buttons and control elements. They are not made to be controlled by a coarse pointer, such as a finger.