In my opinion, the only things that should ever be edited on a live album are technical gremlins, i.e. mics giving up or guitarists breaking a string and having to "manage" for the rest of the song with what they have left or when certain instruments are too far down in the mix. Bad vocals and instrumental mess ups should be left in, as a "live album" is meant to be a record of what actually happened at the gig, not what happens in a studio a few weeks/months later.
If the vocals are that bad that they have to seriously edited and auto tuned, then the vocalist needs to either get better or leave, the same goes for any musician who messes up his playing, practice, get better or let someone else do it who CAN play live!.
If groups (and I know several do) feel that their live albums should be basically re-recorded in a studio, then they should at least be honest about it and state that on the back cover with all the credits, thanks etc.