It demonstrates that the person is easily led into accepting modern inventions as 'tradition' and their complete disregard for the environment and the safety and wishes of local people in their willingness to satisfy their own selfish desire for a "spiritual" photo-op.
Whoo, Bradypus, dial it back a bit.
I agree that it is not good for environment, neither the human nor the ecological, but I understand the need to put a final cap on what was, hopefully, an amazing experience for the walker.
Personally, I couldn't imagine burning my items at the end of my Camino. They had been my closest companions for weeks and weeks and had seen me through too many adventures to count. If I could now hang my boots off my rear view mirror of my car, I would.
Anthropomorphism, anyone?