I think you make an excellent point. Most of my experience has been in the Southwest, primarily Arizona, and in California. You can either hike or forage, but hiking, in terms of covering significant miles, while foraging, just doesn't work.

I love wild strawberries, pinyon nuts, and prickly pear jam, among other wild products, but if i want to cover ground, I bring food from the supermarket. Being in a survival situation would be a whole different ball game.