Of the popular music bands I've seen live (several dozen would probably be an accurate estimate, not as much as I'd like to, but a decent start), all of the bands that I've really respected have been able to get it fairly close. Of course the little quirks, the third and fourth layers of guitars, that kind of stuff, has to be lost, but the musicianship and skill I hear on the recording is still there. I'd be very disappointed if I saw a "pop" artist at a performance and their playing was much worse than it was on the album.
Oh, I realize that. I love studio editing, production - that kind of stuff fascinates me. But I still don't think a serious artist should use technology to give the illusion they're a more talented artist than they are. If you can't play a part for a song you write, you should practice harder - not get the computer to do it for you. There are a lot of fascinating, valid uses for technology and computers, but fudging sloppy performances is not, in my opinion, one of them.