I think Americans mistake people saying 'erm, excuse me, you chaps are blowing smoke up your own butts' for jealousy.
I think that there are benefits to being patriotic and proud, and there are some amazing things about the US, a few of my fav modern thinkers are American, Noam Chompky, Ken Wilbur for example.
However, all the posturing, chest beating, and larging oneself up does get tedious, which is why threads like this appear.
AND there are really amazing things, people, industries and economies happening in other countries in the world. It just seems that a lot of people in the USA are rarely aware of this.
The world uses a different way of ranking place in the Olympics, and even when presented with the facts, there is denial.
People get angry when they think they are not being listened to, which is the case in this thread for some.