Have you actually used a touch screen on a Desktop? I'm not being snarky here; I genuinely believe that you should actively try to use a touch screen with a Win8 desktop before deciding one way or the other. I do it every day, and while it is not great for everything, there are some places where it is really nice.
For example, I love having a touch monitor when I'm reading a long Word document. Why hold a mouse and use the scroll wheel as I read a 35 page spec when I can sit there casually and flip through the document as I read? Or, if I have two hands on they keyboard typing and need to switch to another window, it can be nice to just tap the screen, rather than grab the mouse, navigate to the correct place on the screen and then click the button. Touch isn't perfect for everything, and I use the mouse plenty, but it's nice to have both. The key for me, however, was that I initially had to force myself to use the touch screen - I just wasn't used to it. Once I got in the habit of using it, however, I've found it has it's place and can be nice.
That would make sense on laptops and other small devices, but not so much if you're sitting 2-3 ft away from 2-3 large screens. Which is not uncommon for programmers and designers these days.
Right now, from where I'm sitting, I can't touch my desktop monitor without leaning forward uncomfortably. Even if large touchscreens become cheaper over the next few years, my arms aren't going to get any longer, and my field of vision isn't going to get any wider (larger monitor = sit further away). In this situation, touch isn't simply imperfect, it's physiologically impossible. It'll be even more impossible if your "screen" is a 50" plasma TV on the opposite wall.
The other practical problem I see: fingerprints. I never touch my laptop screen because I'm looking at it all day and even at full brightness you can see previous fingerprints.
Haha, you're right. I have dry skin, so I make heavy use of hand cream... which doesn't play nicely with touchscreens at all. The smudges are especially annoying on glossy screens.
For example, I love having a touch monitor when I'm reading a long Word document. Why hold a mouse and use the scroll wheel as I read a 35 page spec when I can sit there casually and flip through the document as I read? Or, if I have two hands on they keyboard typing and need to switch to another window, it can be nice to just tap the screen, rather than grab the mouse, navigate to the correct place on the screen and then click the button. Touch isn't perfect for everything, and I use the mouse plenty, but it's nice to have both. The key for me, however, was that I initially had to force myself to use the touch screen - I just wasn't used to it. Once I got in the habit of using it, however, I've found it has it's place and can be nice.