There is the stereotype of the ignorant Yank who still argues his point loudly and aggressively even though he has no idea what he is talking about. Do you guys get taught that kind of sentiment in school?
I believe I missed Self Righteous 101. You used a key word here stereotype. We all know while they may have a 'grain' of truth to them, typically they do represent a warped view of the group - throwing out the middle and leaving the extremes.
I think another reason is that like it or not, the USA is pretty much the hub of the Western world these days. Hence if you live in the "centre of the world" (note the sarcasm...) you don't really have to look far afield, do you?
This statement does have a lot to do with the attitude of the 'stereotypical' US citizen. This statement also has a lot to do with the vitriol towards the US. Whether it is jealousy, fear, or any other emotion, it is quite obvious to me that the end result is a severe dislike or hatred towards the US. On a much smaller scale this may be compared to seeing the smartest kid in the class getting a faling grade on an exam. People find comfort in seeing successful (no matter how they got there, legally or not) fail.
I hope that in some small way I've shown you that not all people from the States are 'ignorant'.
--I find that the harder I work, the more luck I seem to have. " - Thomas Jefferson