I think it's just a matter of time for that trend of exclusively mobile/dumb devices to start reversing especially as phones/tablets increase in processing power. Canonical already showed us it is possible to run both Android and a full desktop OS on the Android kernel years ago[1], MS Surface tablets are basically laptops without a fixed hinge between the keyboard and screen.
I see at least one clear profit motive for the industry here, let's say you have a "Desktop enabled, smart" smartphone, you'll probably want to buy a dock, screen, keyboard, mouse, productivity software, etc.