Whoaw, it is OK for me to discuss "the meaning of" or "the difference between" acting/performing and experience in Live-shows.
But don't mess up with the traditional "recording". Your argument is so wrong in so many ways in this discussion -- I, I... can't even point my finger on it. Literally, I would need Optimus Prime for this, pointing with the Empire State Building from 100 miles in the air all along the horizon.
To be honest: I have only two concert DVDs here because I am a much more fan of going to venues, paying for my tickets and seeing my favorite acts live. I even travel into other countries just because to see bands which don't find their way to Germany because they aren't popular here or are doing special concerts (acoustic sets or playing an entire album released 10 years ago). Pink Floyd playing in Pompeii is for instance art in my opinion, not a lame concert recording. This cannot be compared to animated characters playing guitar or so, because they are not REAL, they dont have those skills, they are lifeless, animated batches of shimmering pixels. I don't even get this new trend of bands playing a concert which is streamed into cinemas all over the world... thats like,... fake.
I even think this Gorillaz-thing is not worth the money at a concert, because it is a fictional band with comic characters. One part of the experience of a live show is the interaction. So, how are they supposed to interact with the audience. It is just a tape. A tape in a empty hall with lots of fooled, sweating people in there.
Maybe they had a great evening. And if YOU like this, go for it. Like it, it is just taste. But I disregard this with every faser of my körper
P.S: ... Until a holodeck comes true.
just a nice trick, but not very usable. 
