Remember how iPad fans used to laugh at the idea of Windows on a tablet? Chances are they're still laughing. Everybody else seems to have re-calibrated their opinions though and through a combination of falling iPad sales and growing Windows tablet sales iOS is in danger of losing second place in the tablet market to Windows.
Android is far and away the leader in terms of sales volume, however even Google's green monster lost market share to Microsoft in Q4 '16. A clear sign of the utility of the true Windows experience on a tablet device.
iOS and Android (to a lesser extent) tablets are limited in the amount of everyday computing capability they offer to users. Windows remains the real deal.
Whilst Google seems to have understood this message (and has merged Chromebook and Android into a more functional device likely to appear in tablet form any day now) Apple is (outwardly anyway) disparaging about the idea of a hybrid full computing device based on a Mac.
Even as the iPad under-performed the tablet market in 2016, Mac sales under-performed the PC market. People want devices like the Surface - and every mainstream PC manufacturer has at least one in its range.
There's no doubt a MacOS-based iPad would steal sales from both Mac and iPad lines. That's a risk Apple has been prepared to take in the past - always successfully. By not having such a device in its range Apple really seems to be pushing customers to Microsoft.
The main objection has been that MacOS would be very difficult to make touch-friendly. That seems highly unlikely. If Microsoft is able to successfully offer the Start Menu in touch and mouse friendly versions to suit the use of the device, can it really be that difficult for Apple to do the same to the Finder. It already has the successful iPad interface and MacOS touchpad gestures to build from.
I choose to believe that Apple is marking time with both iPad and Mac updates, waiting for the day when it can launch a tablet device which has full computing capability. Any other interpretation suggests a very dangerous mis-understanding of what customers want of Apple.