I wouldn't have learned about JJ Cale if it wasn't for Eric Clapton and Lynyrd Skynyrd, JJ would have been anonymous. But that is part of his mystique and appeal because in reality he was a guitar picker that decided that writing songs might fare him better than his playing. Therefore, many people are JJ Cale fans while not even knowing his name but that didn't bother JJ Cale, "What is nice is when you get the check in the mail." I'd say he made the right choice. JJ Cale was very modest and just plain cool.
Condolences to the Cale family. There will never be another like JJ Cale and he will be missed!
A brief list of those who covered JJ Cale's songs:
The Allman Brothers
Lynyrd Skynyrd
Eric Clapton
Grateful Dead
Johnny Cash
The Band
Chet Atkins
Freddie King
Maria Muldaur
Captain Beefheart
Widespread Panic
Those who cite JJ Cale as a major influence:
Neil Young
Mark Knopfler
Bryan Ferry