Example of how current PC interface is bad:


Try reading a helpfile using the keyboard. Please, try! It's really tough going, for instance navigating between the panes. And where do you learn the keyboard shortcuts? Do you? Most people don't.

Imagine navigating with a TrackPoint.
Use left/right to go thru the left panel. A click (that's a light tap on the trackpoint) expands or collapses a branch. A double click expands or collapses the whole subtree. More pressure means faster navigation. Each new line returns a 'prod' (trackpoint IV allows feedback via a rod going thru the middle).
Use up/down to scroll thru the panel on the right. Harder press => faster scroll.