The NPS has an even more specific version of this: the overwhelming majority of Americans visiting a park will not walk more than 1/4 mile from their vehicle. So everything is designed to reinforce this behavior as much as possible, which (a) means that the majority of people get a richer, more dramatic and/or more informative/eye-opening visit (b) the backcountry is left alone, both for the other animals that live there and for the rare humans who will head out there.