They do the same thing over here on the tonight show with Jay Leno. Its called comedy. I recognize that guy in your clip cause
I posted a YT video of him on my blog, and from what I can gather, he is a comedian who does a comedy show.
Back to people being idiots, America has a big population. And level of education seems to be that on par with the rest of the world, but there are lots of other factors at play here. Like Americans being close-minded inconsiderate, rude and ignorant of how the world works and other countries. There are a lot of Americans who claim that America is the greatest country who have never left the country.
And then there is the religion thing. (probably best discussed in other threads)
Someone could go onto any other country and ask the same sorts of questions and get the same results and edit them together to make comedy. It doesn't conclusively say that the citizens of that country are stupid. It only says that some of the citizens of that country are stupid.