I've been aware of Onion's satire for quite some time but after going to their homepage and seeing that they don't make it clear that's their purpose, I can understand why other countries don't get the humor and see them as a legitimate news organization.
Unfortunately it also points out the dangerously great divides between cultures on what's funny and what isn't. It's quite frightening seeing we're right in the middle of an information explosion even more easily accessed through technology and all for free.
You can lead a horse to water, but you can't make it grow a sense of humor.