Basically, we wanted to re-invent the wheel. We realized, of course, that this is potentially a recipe for disaster. In our defense, I'll say this. In every way. Mice do not.
Mice are good at selecting tiny elements on the screen.
Joysticks are not. Little bits of text look fine on a 1024x768 display from a foot away. Little bits of text look like hieroglyphics at 640x480 on a television 9 feet from your couch. Computer games have vast hard drives that let you save tons of data. These notions, and many others, were the hobgoblins that plagued us when we sat down to write the Lost Design document.