On the original question – whether you give (want) any background etc depends upon the environment you're in. In some places where the audience is not gathered to listen to "traditional", or even "folk" music it may not be appropriate; so at an open mic, karaoke-style set up or a in heaving, noisy pub bar it's probably best just to sing anything entertaining, whether traditional or not. In other contexts (and, possibly contentiously, I'd put folk clubs in this category) it adds to the enjoyment to know something about what you're listening to – particularly since the very nature of traditional song is that it does have an historical story in addition to the story contained within the lyrics.

If you don't actually know anything about the background, the concept of the song being "traditional" is superfluous anyway – without background it's just a song. How would you know you were singing a traditional song if you didn't know its history and provenance? Isn't the provenance part of what sets traditional song aside? By claiming an interest in "traditional" songs we are showing that we have looked into the background of the song – so we've already moved into the "education" sphere.

Obviously the original comment ("not for a further education class") was phrased to imply the worst sort of presentation of the background to a song. No-one wants to listen to something badly presented whether it be a song or a lesson/lecture but to suggest that you should never talk about, or have the opportunity to learn about, where the song came from and the journey that it has taken seems to me to miss some of the essence of what distinguishes traditional song from any other song.

In addition, did Mr. Davenport, never find enjoyment in learning something new? At some of the evenings I go to I gain a lot of pleasure from learning about the songs. When I stop wanting to learn it'll be time to give up completely.