I find it odd that there is such a strong reaction to pitch correction but not to quantising. One is to correct imperfections in pitch and the other to correct imperfections in timing. Arguably, fixing the timing has a much bigger impact on the groove and feel of a song so could be considered the bigger sin.
By the same token, we use dozen of effects on guitar and bass, so why shouldn't vocalists? Sure, it's a matter of taste and some consider that it gets overused, so why isn't distortion/overdrive considered overused when it is far more prevalent?
I'm not entirely sure of my own feelings on the matter, so I am just trying to keep an open mind.