My point was acknowleding that you can use mouse/keyboard to operate W8, but you can't use touch without buying a device with a touchscreen, which people simply aren't doing.
I believe the main reason for this is the stress placed on a person's arms being unsupported when stretching out to use touch on vertical screens, which are several feet away from the user on desktop ... whereas the arms, hands and wrists are supported by resting on the desktop when using mouse/keyboard. Plus the added advantage of the speed of touch typing on the keyboard, which cannot be done on a virtual keyboard. Also with drop down text menus individual selections are too small for fingers to locate but mouse pointer can.
Then there's the price factor. And of course the "finger printed" screen problem ... probably loved by NCIS though, lol! And the outstretched hand obscuring a large part of the screen.
With laptops the screen is close, and while touch can be used, my experience is that it's awkward.
With horizontal screens touch is fine because there is no strain on the arms as they hang down vertically. And the functionality of touch is necessary on small screens such as mobile phones and tablets of course with no keyboard.
RT with detachable keyboard would sound a good multi-option, but this has not panned out in the market place.