Discussion so far seems to have been confined to some fairly recent songs, where there is perhaps a presumption that the original performer's version is "right" by definition, though that doesn't prevent anyone from preferring someone's different version.

With traditional songs variation is part of the package and there is often no right or wrong about it, though we may tend to prefer whatever version we have come across first.

Over the years I've heard plenty of songs done in ways that I have personally disliked intensely. Sometimes it's purely a matter of taste but often the problem is with the accompaniment, for example an out-of-tune guitar or an accompaniment that is too loud in relation to the voice and drowns the words.