However, the American behavior the author is describing is more attributed to how American social norms don't force anyone to "read the room" and "know your place". At least, not as much as Italians and Koreans. Americans have simple rules they abide by, like general etiquette and the constitution. And Americans are brought up to neither refrain from nor judge others acting within that boundary.
So I don't agree Americans are "tasteless". I find Americans to be more tolerant and accepting, at least compared to cultures with longer history. And that is the American "taste" in my opinion. This has its cons, one of which is someone from my culture thinking they are oblivious to others around them.