First off, it’s Fox News. They claim to be fair and balanced but they cannot hide their Conservative leanings.
Second, news here is more about ratings than about content, so you have to show the audience stuff they care about or they will just change the channel. Since many Americans could not care less about the rest of the world, they don’t want to hear about it. (I could digress about how self-centered they are, but it’d take me too long to type for something so far off-topic.)
Third, many Americans are intellectually lazy, sometimes to the point where they are proud to be uninformed. This relates in part to #2 since they don’t want to fill their heads with “useless” knowledge. This also goes into why so many people can’t figure out computers, why so many people don’t read instruction manuals, why our math and language skills are so poor compared to the rest of the industrialized world, and many other things.