He's a either a narcissist or lacks empathy or media literacy and/or all three. Since he's been indoctrinated by the right he believes that Clark didn't bring his culture because they don't recognize kindness, compassion and respect for other human beings as being Superman's culture. They genuinely think he learned that by growing up in America, and basically took the movie as being like "He's this way because he's American" not "He's this way because he's alien"