Wow, thanks so much for all the replies to my initial post. I wish I could respond to all of them. Overall, I am more convinced that
I agree about the safety issues and can see how people could jump into ultralight backpacking without sufficient preparation, equipment, etc. One "tip" from the book I mentioned, which I didn't quote, is:
"Comfortable and safe are vital! Anyone can go out into the mountains with a tiny amount of gear and suffer-it's easy to be cold, hungry and ill prepared. Ultralight camping should be delightful, not stressful. The challenge is to succeed with only the gear that's absolutely needed."
One example that stood out to me is that the author heavily recommends bear spray in bear country, to the point of not including the bear spray as part of the overall pack weight. On the other hand, he's not a big fan of bear canisters, and uses a rope system that, he says, is just as good.
Also, various people asked about the wet feet and the gear out of trash. Regarding wet feet, he advocates river crossing with lightweight boots on, and just letting your feet dry as you go. I don't think he would suggest this for a winter snowshoe hike, and the implication is that the weather is okay. And as for trash, as others pointed out he's referring to the cat food can stove and the good old used plastic water bottles (not those heavy nalgenes), and, beyond that, using your imagination. The point is that UL gear doesn't have to be that expensive. And if you take good care of it, it will last you.