That cool factor is outweighed by history: touch screens failed as the primary interface for desktop computers and similar constant-use devices because of gorilla arm. This is the heavy, dragged-down feeling arms get when they are held forward or upward for extended periods of time. Short interactions with touch screens, such as those used in automatic teller machines, are not a problem. Nor are very small screens, like those on PDAs. Making the monitor angled backward in a more horizontal position, as shown in this video, can alleviate the problem somewhat.
Gorilla arm is also part of the reason why we have speed ratios on mice and trackpads, where the slightest movement of the hand moves the cursor a much larger distance across the computer screen. If it was a 1:1 ratio, repetitive stress injuries and the like would be far more prevalent.
Tip: you can ease the strain on your mouse hand by setting your mouse as fast as possible. For further tweaking, on OS X you used to be able to, and perhaps still can, install the Kensington MouseWorks software. Even when I haven’t had a Kensington pointer device, it let me set my mouse settings hyper-fast and hyper-sensitive. It takes a day or two to get used to, but after that you’ll need only to barely budge your finger to get the cursor to go exactly where you want it. Your tight tendons will eventually relax.