Chris, you got me curious about the three people you mentioned so I checked them out. I've been looking around for information on the history of going light for quite some time now, including reading the posts on Mallory at Outdoor Magic. The more I read the more I come to the conclusion that backpacking with lightweight methods is definitely not a recent phenomenon. People have probably been doing it ever since we first started walking long distances. Certainly when I travel around here in Japan and see some of the really old timers, like the backwoods foresters, mountain edible plant gatherers, and mountain creek fishermen... one of whom carried two mandarin oranges for his entire day's meal... and their extremely simple assortment of gear I have to ask about the extent of my knowledge and of their toughness. Recently in the biggest backpacking magazine in Japan, "Yama to Keikoku" (Mountains and Valleys), there was an article on an 81 year old man who has been walking, non-stop, for over 8000 days every day the same range of mountains with just an old ski pole, an umbrella, a day pack, a homemade, waterproofed straw hat, a trenchcoat, a machete-like knife, a pair of rubber boots, and a shawl-like waterproof canvas throw that he drapes over his shoulders and pack when it rains. His toughness and simplicity and complete lack of need for all the stuff we here all seem to need so badly puts me to shame. Now he's aiming for 9,000 days.
I checked out Thomas Hiram Holding and came across the ALC, the Association of Lightweight Campers... founded in 1901. Doubtless we could continue to go further and further back. The Ice Man traveled very light in the mountains, too. Even today the San (the Bushmen) in Africa travel with nothing but a bow and some arrows. I think we have a lot to learn about going light.