"..........and can't remember words without holding a crib sheet, and so is incapable of interpreting a song because they have to read it? "
Everyone who knows me, knows that I ONLY sing or verse with the words in front of me. Not a "Crib Sheet", bacause that implies cheating. From London Symphony Orchestra to Les Barker, there is a well set precedent for words/music.
To presume lack of interpretation as a natural follow on to having words is an insult. I spent many years running and attending Folk Clubs before I ever sang. I decided that the worst public failing was not getting the words out. Once the performer is seen to falter all the audience confidence is lost, they worry/feel for the performer, getting to the end. Any thought of following the story or getting into the song is lost.
If a singer is using words this at least assures the listener that there will be an end!

As for interpretation this is so much easier to perfect when the printed word is in front of you. I can also read the words of the following verse and if necesssary drop and or alter as I go along. I still have the problem occasionally of seeing the words through the emotion of some of my favourite songs.

As we can see from this thread, we all have different ideas of perfection v performance, and although some may need a humour transplant we are all singing the same song really.

Happy ******mas