[jvanderbot]

Imagine you program a robot to "put away" a towel. Then it opens the door and finds there's a cup in the place already. Now what? Or a mouse. Or a piece of paper that looks like a towel in this lighting. Or a child.

Imagine the frustration if the robot kept returning to you saying "I cannot put this away". You'd get rid of the robot quickly. Reasoning at that level is so difficult.

But then imagine it was just a towel all along - oops, your perception system screwed up and now you put the towel in the dishwasher. Maybe this happens 1/1,000,000 times, but that person posts pictures on the internet and your company stock tanks.