Five reasons for the demise of the interest in folk music in America was that:
1. It was killed by the academics such as D.K. Wilgus at U.C.L.A. who refused non-traditional performers such as Joan Baez to be on the folk song programs, not allowing for a wider circle of interest by audiences who could have been exposed to traditional folk and learned to appreciate it. Alan Lomax was also inconsistent on this issue, setting an arbitrary standard for what he considered "folk", often vituperatively protesting exponents of the commercialization of folk music such as excellent musicians, Bud and Travis, yet embracing the Kingston Trio as OK.
2. Young people who once had an interest in folk music found it to be creatively stultifying and turned to rock or pop instead, finding there a creative place in that form of music before it became corporatized.
3. Young black musicians found a white oriented "folk music" too restrictive so turned to "rap" and "hip hop" or "blues". Today that's being remedied by such exciting black groups, The Carolina Chocolate Drops, Guy Davis, Erik Bibb and Sweet Honey in the Rock. Black folk musicians have not surfaced in the UK because the anti-black racism is ignored there and not as not overt as it is in the US.
4. International folk music was labeled "ethnic" and often outside the realm of what many people thought was "folk music" however it flourishes in other parts of the world where Commercial American Musical Imperialism hasn't taken hold.
5. In America, arbitrary distinctions were made classifying different "branches" of folk music in record bins such as "celtic" or "blues" labeled by pedants and recording salespeople often excluding the best part of folk music, an amalgam of various previous folk music forms, perhaps standing the chance of being tomorrow's legitimate folk music.