Much of modern music is perfect to the point of boredom: Singers not hitting the right notes are tone shifted. Drumkits are replaced by beat samples. Mistakes are corrected. Nothing is left to art.
Raw music is far more interesting because it's believable. When I hear Johnny Cash singing his version of the Nine Inch Nails track, Hurt, it feels real, as if from the heart. That doesn't happen because he's pitch-perfect, which he is not, but because when the heart reaches out it's in spite of perfection. I dare say Neil Young finds his way into this discussion as well.
Some artists have their craft down so well they can evoke emotions in their music without worrying about technique, hitting all the right notes, but that's not as important as hitting the right emotions. I'll give up technical perfection for raw grit.
If it's too slick, too highly polished, too shiny, I question its authenticity.
I don't care for perfection as much as I do emotion.
When an artist's heart can connect with my own, despite any technical missteps, that's perfection.