I have no quarrel at all with a cockney lad singing Leadbelly songs as long as they aren't done with a cockney accent. If you really want to laugh your socks off at how ridiculous this might sound then I suggest listening to someone that came along later, Billy Bragg doing Woody Guthrie.

Can't see anything particularly absurd in people singing songs from abroad in their own accents. After all, nobody suggests that the Dubliners should have put on a Norfolk accent to sing the Wild Rover.