According to the statistics I have seen, for developed nations, America is considered to be one of the most productive countries based on hours worked and value of goods produced per hour worked.
A lot of accusations are cast at people receiving government assistance (and the unemployed) these days. Basically that they are lazy and want things handed to them, but their really isn't any basis for these claims. I don't really know why some Americans are so willing to spit on their neighbors, but I find it disgusting.
Most Americans work hard and don't mind working hard. I'm not really sure where you get the idea that they have a poor work ethic.