Music, especially improvised music is a conversation between instrumentalists.
Unless you are insane, can you really talk to yourself for very long and be engaged or engaging? However when talking to others especially if it's the right people a conversation can go on and on because it IS engaging.
So I think Diliberto has a point. A one man show ultimately isn't that interesting to watch for an extended period. Even the Metheny Orchestrion idea would get old quick and that guy has chops galore and it has a visual element of the instruments on stage instead of sounds coming out of speakers from samples playing from some device. Also I checked out the Metheny video on his site www.patmetheny.com/orchestrioninfo
and he said something I thought telling.
He mentioned when a musician is in a situation such as overdubbing and playing to themselves there is an imprint like a fingerprint to fingerprint (see the video at about 5:22.) I think he simultaneously hit on what is beautiful about the process and what is also a dead end about it. Because if you are only responding to yourself then it's much like having a conversation with yourself. It's one sided and probably not that interesting in the long term. I've noticed the same thing when doing live looping which is a common tool in electronic music.
In watching Metheny with his Orchestrion I was initially excited (in part because I love 19th century Orchestrion's) but quickly realized what he was getting out of the instrument was no different than what I have heard him do with other musicians. I would have been more excited to hear him use the process to come up with some new directions in sound.
When I see live performances part of what engages me the most is seeing how musicians get sounds out of their instrument and getting a sense of how the music is created. There is also an interplay in imperfection that is fascinating. Human beings flow, their tempo swings and the emotional connection that pours out from a really great set of players connects with the audience.
Disconnection only yields more disconnection. The man playing the computer is disconnected from striking the head on a drum, the audience is disconnected from seeing the force of the blow on that drum and hearing the explosion of sound it creates and so on. Disconnected. Disinterested. Disengaged.
The electronic music genre needs a shot in the arm. Badly. Getting three or four folks on stage playing together might just be the ticket to bring more interest in what is happening both on stage and off. Otherwise in performance you might as well resort to getting some Solid Gold dancers or Fly Girls or what have you to sell all that mouse jockeying.