Jim - read any of Ron Cohen's books such as "Rainbow Quest". You can also check Robert Cantwell's "When We Were Good", Dick Weissman's "Which Side Are You On", or Scott Alarik's writing. All recognize the influence of singer-songwriters through the ages.

At the same time, I do not think that any of them, nor would I, disagree with your definition of the traditional side of folk music.   I am not disagreeing with your desires for folk clubs. You should be entitled to program any style you like. The rest of the world should have the same opportunity and the contemporary definition of folk music has just as much right to claim title to the words.