Why should we sing folk music?
Because we must...
imho there's no other answer.
Anyone who does it for profit or for status is doing that for their own reasons, and you'd like to assume that they were interested in the first place to preserve and augment the traditions of their own people.
Imho we all have from within an urge to express and preserve our own heritage- those who don't are among the quacks and dictators who seek to cut us off from ties of family and friends, usually to insert themselves in some way to profit from the lack. Cults do it all the time. Making money out of the unsettled is one of the growth industries of our time.
Which imho is why those who use smoke and mirrors for gain are eager to excise the traditional warnings inherent in the old stories. Who can hear Long Lankin without thinking of the dangers in taking insufficient precautions against thieves in the night? And the world is full of false nurses who take some cash to let the predator in.
So we sing them because their is an urge to communicate the old stories. Because we must...