Why does a 2 floor building's elevator have need of buttons signifying which floor to go to? Well Armond, that is a good question. I would have to say that there doesn't seem to be a need. The top button for up and the lower button for down.
However, in my experience with user technical problems anything can throw off concentration when fear comes into play. Those who are afraid can muck up anything. Hmmm that's kinda ninja-like too, a lesson to not be afraid. So do elevators evoke a sense of fear? Perhaps. I don't mind them personally, that is if they are not free falling 20 stories, but I can see how some people would be nervous in a elevator without a floor number beside the button. They would forget what floor they are currently on, panic and begin hitting all of the buttons.
In this scenario, with only two floors, the smart ninjas will be in the stairwell.