Anything that is recorded and reproduced by "mechanical" means, whether it be a photograph or a sound recording is by definition artificial. There are times when I've softened skin in portraits a little because my medium format digital camera and lenses are just too resolving for what the subject wants to see.
When it comes to recording, I prefer to punch in any parts of vocals that are sharp or flat. But that said, I'm not trying to get every single syllable to be within a cent or two of perfect pitch if it's going to interfere with the singer's natural expression. For clarity, I'm not talking about accepting a performance that is in any way obviously out of tune.
I don't listen to the type of music that uses auto tune to make voices sound like they were vocoded.