"The 1954 definition was intended for use by academics, to set out parameters for academic study."
Sorry Howard, it was no such thing.
It was an attempt, largely by academics, but also by singers too, to make sense of a specific body of song that had caught the imaginations of singers and scholars alike around the time the BBC was carrying out its 'mopping up' campaign (aimed at producing a series of programmes for public consumption - 'As Roved Out' .
Organisations like Topic Records (non-academic) pretty well adhered to it, as did editors of "Folk" magazines and "folk" song collections. There were clubs who ahdered to it so closely that they wouldn't let you in with a musical instrument and who asked you not to sing recently composed songs, even if they sounded 'folk'. Events like the Keele Festival, with with lecturers/performers like Bert Lloyd and guests like Harry Cox and Jeannie Robertson comfortably catered for both scholars and folk fans without there being any conflict of interest or any doubt what was on offer.
There were always people who latched onto the label because they had no identification tag of their own, and it when these gained dominance that the problems really began and audences were no longer given a choice in what they wanted to listen to.
"Also, language has moved on and "folk" has a much broader meaning than it did in 1954"
Not really - what has happened is a fairly loose definition has been abandoned totally (not replaced) in the interest of people who neither understand nor like folk music (too long, finger-in-ear, et al).
Jim Carroll