Nobody thinks that.
But what is quite visible, I think, is an arrogance of many Americans who simply think that they are the norm of everything and everybody else must have it in the same way or else its automatically wrong.
And, maybe, just maybe, Americans happen to be especially loud about what they do not know...?
Third, maybe a different education system. While people in Europe, Asia etc must memorize from elementary schools facts about the world, its history, geography etc, I heard (I am not sure if it is true) that in the USA ppl are more learning how to think and how to express their opinions than memorizing facts. To be "individual". Which can be better for everyday living, but, of course, you lack some knowledge about the world what other people know, then. If you are not interested in it later.