> Is it because 90% of Americans don't even have money left to invest after their cost of living?
In part, I think this is true. But "cost of living" is maybe a bit broad. Most of these 90% of Americans have a poor grasp of personal finance, and spend way more on unnecessary crap than they should (car loans, credit card debt, restaurants, alcohol, coffee, cell phone bills, cable tv, etc.). This isn't to say that there aren't systemic problems that increase wealth inequality (there are), but a big part of the problem is just good old fashioned consumerism.
In part, I think this is true. But "cost of living" is maybe a bit broad. Most of these 90% of Americans have a poor grasp of personal finance, and spend way more on unnecessary crap than they should (car loans, credit card debt, restaurants, alcohol, coffee, cell phone bills, cable tv, etc.). This isn't to say that there aren't systemic problems that increase wealth inequality (there are), but a big part of the problem is just good old fashioned consumerism.