Harvest Moon

Every time I go to a coffee house, somebody goes onstage with their guitar, and, invariably, they clear their throat, shuffle their feet nervously, peek shyly out at the audience from under their bowed head say "This is, uh, this is a Neil Young cover."
We are then, as an audience, are subject to a mediochre rendition of Harvest Moon.
Why is it that every bedroom folk singer who creeps out of the woodwork sings this exact song? What is it about Neil Young's Harvest Moon that is so attractive to so many budding guitarists?
Its probably some unspoken cultural right of passage for folk singers. They have become a secret soceity, shifting away from from their former prominance like the Knights Templar shifted, like how masons stop being creepy once they get old, and turn into smiling old men in funny red hats and small cars. Shriners. Really, when does the secrecy and mysticism of the Masons drift to an organisation that brings a circus to town every year?
In short: Secret soceities are ineffable because they are inpenatrable. I can never understand why every ametuer folk singer must sing Harvest Moon, yet it still happens. This is probably why the audience wasn't shocked when Stuart did it, too.