This is just not the common case. Generally speaking, the US does give disproportionate rewards to the 'high-end' of the curve so to speak. However this often comes at a cost to everyone else(or the following generation) whether they realize it or not. It's simply harder to notice this happening when it's spread over a generation or two. Examples being health care, the economic pyramid schemes, 'education', care of veterans etc.
Top tier American schools are highly-overrated and highly overpriced these days. They are a much bigger and slower bubble to burst over here. http://www.theamericanscholar.org/the-disadvantages-of-an-el...
I believe the key phrase in this article is "entitled mediocrity". The author also spent at least 25 years as a scholar and then Professor at Yale and Columbia.
With all that being said, America is still a great place. It just might be better not to look for the rewards in all the popular places and using the popular methods.
"Top tier American schools are highly-overrated and highly overpriced these days."
Perception, in this case, trumps reality. The reality is that a MIT degree is worth a hell of a lot more in salary than a random eastern European university. Whether or not the education truly is better is moot - people want in on the USA because it generally will lead to a better life than they've got now - assuming "now" is an underdeveloped country.
This is exemplified in the way the US does everything. Even the mere existence of this site is a profoundly American thing. Canadian entrepreneurs rarely cash out to the tune that Valley companies receive. The richest of the rich in Canada are poor compared to the extreme rich in the US. The best schools in the US kicks the shit out of the best schools in most other places (with a few notable exceptions, of course)... etc etc. The US is a country of extremes, and for many immigrants this is very attractive.
This is particularly true for individuals who have already proven their ability to be better than the rest - America gives disproportionate rewards to the high end of the curve than more socialist countries (e.g. most of western Europe and Canada). At the risk of drawing in Randian thought (which really is the nouveau Godwin's Law), socialist countries restrict the rewards to the extremely talented, whereas America does no such thing (at a cost to the bottom half of its bell curve).