If we were to present a scholarly introduction to every song sung, or tune played, in a session or club, there wouldn't be much music played.
I'm grateful to the many thoughtful contributions to this thread, it has been one of the best I've seen on many forums in a long time. One can only at best make educated guesses as to Bert's motives. No doubt we are all glad for the great contribution he made and I have no argument with his re-arranging, we all do that, but I would have preferred it if he had been open about what he had done.
I've just acquired a copy of "The Imagined Village" on which there is a version, by Billy Bragg, of "Hard Times of England". It has been very much brought up to date with mentions of the Countryside Alliance and people buying second (holiday) homes and closures of post offices etc. All very relevant to today's listener. However, we still have an original. If Bert did adapt rural songs to make them industrial, I for one think that was a valid thing to do, however, if it was at the expense of the original song being lost, then that is lamentable.