I think as well, that if all that is seen is, to quote Lizzie:

"Colours, magic, sounds, words, skies, seas, fishermen, miners, bal maidens, weather, worry, hard times, good times, high times, low times, weddings, funerals, rivers, streams, tors and prisons, exiles and immigrants, tall ships and ploughs...YES!"

and you have no handle on when the song was written and how it came to be that we still have it now (ie when / how it came to be collected) then so much is lost from the song. I am reminded of 'The Bonnie Ship the Diamond' - a great song, I've always loved it and the pictures it creates. But, when I learnt, in an introduction, that it is known that the song was written before 18?? (I can't remember off the top of my head, sorry) because The Diamond was lost in the ice off Baffin Bay that year, it meant much more. (Someone will probably know far more than me about this, and I will probably learn that all that I was told is wrong!)

Someone found that information out because the song meant something to them - not because they were a boring academc, but because they cared enough about the song and the ships / characters in it, to want to know more. For me, rather than making songs dull, detail gives them colour and breathes life into them.