Conrad, it would appear that you've managed to interact on a regular basis with that tiny minority of greedy, selfish, money grubbin' folksingers, who give the rest of us a bad name. I guess in my 32 years of playing music for a living, I've just had blinkers on...'cause I rarely encounter them.
You said: "I also note that in many of the festivals free and otherwise it is common practice for musicians to hide with each other behind fences and far away from the public. Perhaps so they will not play more than arranged but surely not so that they can communicate with the people."
My experience has been that folk musicians interact with the audience members almost constantly! On rare occasions they may hide behind barriers to get away from the odd "fan!?" who is obsessive, and unpleasant.
Mactheturk! Congratulations. Enjoy.