It seems that some people can't bear the words to be changed, others can't bear the music to be changed - but then if that's the case why not just play a CD?
I have a long-running disagreement with friends who always want to listen to the record and "get it right" - but I genuinely can't sing that way (or can't sing genuinely that way might be the right way round).
Could be similar to the "notation" vs "by ear" thing in another thread. Is "getting it right" sometimes a bit of a constraint?
I suppose its two ways of approaching the beauty of a song or piece - one way is to get it right & thereby experience and feel the thing as it was crafted, whereas the other is to use it as an inspiration and a vehicle for your own creativity. So then, perhaps the latter is a little cheeky.
Its like some people appreciate the engineering & design that goes into a wonderful gadget-thing, and others would like to take it apart to see how it works & then see what they could make with the bits.

KRis