I wouldn't say every American should try to be an expat. I think we'd be better off as a society if everyone traveled abroad more. I know most can't afford that, but I'd be totally down for a state funded 'study abroad' program for bright students. Other places have ideas we can learn from (and vice versa)
The average American thinks the U.S is the best country in the world. I say that as an American. To your point if people saw how the rest of the world lives and how happy many of those 7.88 Billion people are they would start being more vocal about our endless cycle of work until you are 85 to be able to pay your property taxes.
For pete's sake, it's not legal in many states to even cover slavery, the indian genocide, or japanese internment in a way that actually holds the US responsible