Truth be told this article is exactly why a lot of (mostly untraveled) people from the US have a really distorted view of the rest of the world.
Also: I think US citizens are a lot more well-travelled than you assume. Sure, they work hard and don't get much holiday time, but they do travel quite a lot in their free time.
In my ignorance I must have interpreted the article like this: 1. Communism = bad, 2. all Communist people lazy = Communism doomed to fail, 3. big Western company comes bringing enlightenment but people no want jobs (couldn't possible have anything to do with lousy pay = must mean communists be lazy), 4. everybody knows in capitalism people work incredibly productively 8 hours per day - except those crazy Yugoslavs
Blame it on the communism still goes hand in hand with the era when the article was published, but today...? Really - "a Yugoslavian problem"?
EDIT (after your edit): Also - where do I say or assume that a lot of US citizens are not well-travelled? Please read again...
The US citizens you hang out with, sure. And certainly, a lot of US citizens I know now are well-traveled as well. But I moved away from an area in central Pennsylvania where there were families who had lived in the same county since the 1600s. Friends who had, by their mid-twenties, never gone so far as New York, let alone across a national border.
It's certainly a mistake to think that all Americans are ignorant and sheltered, and it's great to see that more and more Americans have passports, but it's still very accurate to say that Americans are mostly untraveled.