To sing from the heart not from the head. I think thats why I don't like people reading their words.However, I also think that the choice of material is important. To be credible, to be able to sell a song, I think that the singer has to convey some experience of the song. There are songs I love hearing but would never sing because I couldn't feel them.
I also don't particularly like to hear songs that have no credibility and there are plenty of them in Scotland, especially those which gloss over an historical event with cliches and assumptions.