Its very brave for Alex to do what he did. He was prepared for the wild but when one is hungry there's only so much that can be done to help them. He was bound to die because no one knew where he was, and he hadn't explored the area where he was going to live.
Because there are so few untouched places in America it will be difficult to truly live in the wild. There aren't many people who would be willing to give up everything and burn their money. As Alex said, humans are too invested in the material things they have acquired. We have been given everything we need to survive and there is little need for us to provide any of it for ourselves. I would be ill-prepared to live off in the wild as would many people. But people used to do it. People used to live off of the planet and only take what they needed to. To live with nature is to live with harmony. We exploit nature, we do not live off of it.