Machines wear out.
Software lasts forever. A diamond can be judged in terms of closeness to perfection, but the only way to improve a ball of mud is to add more mud. Any resemblance to the current state of the software market is far from accidental. The canonical diamond might be Wolfram Research's Mathematica. If you'd never seen a computer before, and someone showed you Mathematica, you'd be thrilled to accept it as your definition of what a computer does.