I agree completely. I was just having this same thought after watching some performances from last week. Pitch correction really sucks the soul out of music for me but apparently there are many that don't feel that way because they often get a good response. It seems a bit disingenuous on the part of the musician in this context as well imho, though I suppose that, as you say, it's usually obvious enough to a trained ear.
Perhaps its use stems from self consciousness when comparing oneself to the overproduced mainstream stuff that we get inundated with.
I dunno. What's real anymore anyway?