Very good writeup. He is totally right.
I one time saw a german electronic “band” perform: They put an iPod on stage to actually show the audience the truth… One guy came to stage flipped in the right instrumental track and the singer would give his live singing performance to the backing of the iPod track.
After the concert he simply said: We could have had our 5 people up here with large keyboards and synthesizers and make it look like they hit buttons, but truth is: We simply cannot play this complex stuff live and we thought you should know.
Audience gave ’em credit for that.
I also think that it is about entertaining. I would totally go to a Deadmau5 show, simply because the lightshow etc. is really really good. Also US EDM guys should learn from the Eurodance scene in the 90s: The DJs then, well they hit some buttons, prolly less than today, but they had like dance performances on stage, whole dance crews, awesome lights and lasers etc. etc. etc. It was like a real entertainment show some even storylined. But of course it would shift some attention away from the DJ, towards the show and some people may simply miss the silly handwave or the groovy headphone pose… selfish bunch.