Why do American movies glorify genocide?

American movies glorify the genocide that was commited against the Native American people by settlers. Films like ones starring John Wayne prtray the Natives almost as animals and show the perpretators of the genocide as gallant cowboys and heroes. In reality the Native Americans were defending their homelands and their famillies against foreign invaders and were the victims. These movies are no different than the mocvies made by Nazi Germany to dehumanise the Jews and to justify the persecution of the Jews. Many of these 'Cowboy and Indian' movies glorifying this genocide would have made Joeseph Goebbels prowd. Why do Americans enjoy watching this propaganda?