From this interesting blog post by Nick Heer on Pixel Envy:
But I do truly believe that by building iOS up as opposed to breaking MacOS down — that is, adding functionality within a made-for-touch framework rather than glomming touch onto MacOS — will prove to be a wise choice in the coming years.
With the latest hardware released by Apple, pieces are being put in place. I think about USB-C on the iPad Pro. In a few iOS releases, we will get USB drives supported but most importantly external monitor support. This will enable a new class of software tools and most importantly renewed interest for the platform. Finally, by focusing on iOS for tablet (as opposed to transforming macOS to make it fit a touch environment) Apple, by simply adding mouse support, will transform the whole platform with a snap. Mouse support will come eventually and please a small group of users that are very vocal about it. Apple will benefit. Can’t wait for the coming year of evolution.