It is important to avoid making sweeping generalizations or judgments about individuals based on their nationality or any other characteristic. People are unique individuals, and their behavior cannot be accurately determined solely based on their nationality. Judging someone as an "awful American" or an "awful" anything is unfair and perpetuates stereotypes.
It is essential to treat each person with respect and judge them based on their actions, character, and values rather than making assumptions based on their nationality. Keep in mind that people's behavior is influenced by a multitude of factors, including their upbringing, experiences, and personal choices, not just their nationality.
If you encounter someone who exhibits negative behavior or attitudes, address the specific behavior without attributing it to their nationality. Encourage open and respectful communication, and focus on understanding one another rather than making judgments based on preconceived notions.