(Note: tounge firmly planted in cheek)Maybe it's because thread, polyester or cotton, isn't really the right material for an instrument? Cat gut, steel strings, heck, even rubber bands work better! ;-)
And besides, it seems to me that in a blues/folk music forum, the line between BS and non-bs, at least potentially, is fuzzy at best. After all, these forms of music have been written in response to the concerns of the people.
Find a hot BS thread, and chances are, you'll find the subject for a song...