Nobody said anything about deliberately controlling those fingers to play yourself. Clearly it's not something you do for the sake of the enjoyment of playing,

Nobody said anything about deliberately controlling those fingers to play yourself. Clearly it's not something you do for the sake of the enjoyment of playing, but more likely a demonstration of the dexterity of the prosthesis and ability to program it for complex tasks. The idea of a prosthesis is to help you regain functionality. If the best way of doing that is through automation, then it'd make little sense not to.