There are a lot of people who don't get that the Onion is a parody, either, but the Onion doesn't start each article with "DISCLAIMER: The following is satire and is not intended to be taken seriously. The events described here are fictional and included for comedic purposes." Why? Two reasons: 1) It wouldn't be as funny anymore, and 2) the fact that stupid people are taking it seriously is hilarious.
There are a lot of people who don't get that the Onion is a parody, either, but the Onion doesn't start each article with "DISCLAIMER: The following is satire and is not intended to be taken seriously. The events described here are fictional and included for comedic purposes." Why? Two reasons: 1) It wouldn't be as funny anymore, and 2) the fact that stupid people are taking it seriously is hilarious.