It's not just admitting that the US has faults, it's the study of history as a criticism of the west and an absence of understanding other countries histories or systems. That their western country is the result of luck and oppression. Everyday I talk to people who are quite familiar with A People's History of the United States and Guns Germs and Steel, but then not extending equal standards to any non-'western' country, usually because of total ignorance about other countries histories that don't include their own. This results in a western citizenry that believe themselves to be the villains when their nation acted similarly or more liberally than other nations of the same eras.