Interesting article ... though I'd take issue with :
The idea of a walking holiday — a long-distance journey on foot, during which you lodge overnight and carry just enough clothing, food and water for each day’s stretch — has long been popular in Europe. But within the last few years, these pilgrimage-style walks have sprung up all over the world.
Sure there are many on the Camino who are on "walking holidays", but the pilgrimage transcends that triviality.
I'd say there are three styles of long-distance hiking.
1) Yes, the walking holiday.
2) Backpacking in the US thru-hike manner -- a very different beast, and more sports discipline than holiday.
3) Pilgrimage (including the numerous varying traditions of it).
The three styles have their specifics and share some commonalities with each other, but each has a unique perspective in approaches to it and goals.