No, when he says "Americans are the stupidest people on the planet" what he means is no one has called him on the asinine "statement" in his movie's TV ad which says:
Fahrenheit: The temperature at which air is ignited
or something like that. Fahrenheit is not a point of temperature, nor does air "ignite". Moore and the people who work for him are just as ham fisted about science and literature as they are at political propaganda.
Fahrenheit 451 is the temparature in which paper burns. His book was about a future when books are banned. The main character is a fireman, who in this future is not a person who puts out fires, but finds illegal books and burns them. The book should be on everyones reading list.
If memory serve 411F is the temp that paper ignites.