Anyone who has used the HP Touch smart line up computer or similar PCs having desktop touch screen capability can best tell you why those are not good for human.

Most people quickly reverted back to the keyboard and mouse instead of touch screen interface. And it isn’t because of the software or touch technology.

The problem is that you get tired keeping your hands up and on the screen for a long period of time. Here is the Video which best explains you about..

10/GUI from C. Miller on Vimeo.