There are arguements on all sides but from one who is knew to this game learning a song fully both words and lyrics makes you practice all the more and is therefore beneficial to all. No one is asking as far as i know for perfection but simply that the songs are learnt
before being performed.
With regards to poetry at folk clubs i agree with the organiser, i cant see poetry societies welcoming a person with his guitar, bango, harmonica, etc, etc
before being performed.