Walkers love to wander unencumbered for hours on end. There's nothing they like to do better than just go forward either into the depths of the woods or the city. Unlike backpackers, they don't like to carry around enough food and supplies to survive in the wilderness for two weeks. They just want a place for the essentials: keys, food, money, and maybe a camera or binoculars. It's speed and lightness that inspires them, not completeness, and a fanny pack perfectly fits their needs.