Slurs are made by the context of their use. In this case, "USAians" is virtually always used in the context of somebody talking shit about Americans, such as y

Slurs are made by the context of their use. In this case, "USAians" is virtually always used in the context of somebody talking shit about Americans, such as you claiming that Americans have no morality. That's a very broad brush you're painting with, characterizing hundreds of millions of people like that, which is a hallmark of bigotry. This makes it a slur.