It is said of Jean Thomas that she was a highly talented woman who also wrote Hollywood screenplays, an exercise which appears to have influenced her non-fiction writing style (to the extent her books on folk music are actually non-fiction). It is also said that some of the folk songs she collected she actually wrote herself. The negative feedback, I think, was a reaction to a certain hokiness and tendency to self-promotion. (One doubts very much everyone in the hills really called her "Traipsin' Woman," as they do in her books.)
Emphasizing quaintness is indeed a widespread vice. They say Leadbelly became very angry with Lomax for making him wear coveralls and sit on a bale of hay at performances!