If you mean "physically capable of being played by a human" then I'd say that a large majority of popular music right now is unplayable by humans, simply due to the sheer amount of digital production that goes into them. Many genres of electronic music fit in this category, but while being "unplayable," all clearly have an author (the composer/producer) and an intent (no matter how shallow or profound).
But if you meant "playable by humans" on a subtler level, I then ask:
Is music coming from a radio playable by humans? Is music written on a sheet playable by humans? Both lack an immediate human operator that is "playing" them, yet despite this difference of media, both are valid forms of music that clearly communicate the intent of a human soul (the former through the radio device, the latter through symbols).
I'd argue that using the computer/algorithm used to generate the black MIDI is an instrument like any other. Maybe you were asking something more along the lines of: how valuable is music that is generated arbitrarily or randomly by a computer algorithm, and does it contain "soul" like music produced explicitly by humans? That is a philosophical question about the nature of art and computational creativity, perhaps without an answer.