"For the most part the term folk seems to be used in the big wide world..."
On the contrary the 'big wide world' has not seen fit to comment on the definition of folk song - certainly not the 'talking horse' one.
The general misuse of the term comes solely from the clubs, where no consensus exists and can cover anything from Chevy Chase to "Jumpin' Jack Flash".
Would you term ' The Penguin Book of English/American/Canadian Folk Songs "academic" works?
Jim Carroll