That proves it is a musical instrument...if it can be noticibly played badly then it must be possible to play it well. I rest my case, well chest really.
I am often amazed how many people have no sense whatever of rhythm or even basic timing. But these same people insist on playing percussion of various sorts. It is of course because Tea Chests, Bhodrans, shakers, Bones, spoons, tambourines etc. look easy to play.