The change in abstraction is the point, and adding touch to Windows or Mac misses the point. It’s like putting a mouse driver on DOS. It does make DOS better, and if DOS is all you have because you misssed GUIs, then of course you should do that. But it’s not the future.
We use the word tablet to refer to two different types of devices:
- The Surface category of tablets. They’re fundamentally a PC with touch screen — these devices promise the same OS and same behaviour of a laptop, with a new input.
- The iPad category of tablets. They’ve got some of the perks of a laptop — a big screen and (if you want) a keyboard — but run on a separate OS which introduces some new ways of doing things.