Glueman says "We've established beyond reasonable doubt that the 1954 definitions have absolutely nothing to do with the performance of folk today". ("We" means Glueman, I take it). Actually I doubt if the 1954 definition had all that much to do with the performance of folk in England in 1954, either. But then, I dont think it was meant to. It was meant to analyse the origins of folk, and how they might differ from classical and popular music.