He's the worst ever because its fashionable to say so.
As much as I hate Bush, I agree wholeheartedly with you on the point that it has become "fashionable" to dislike the guy. Sure, he truly is a terrible president (arguably the worst ever), both for Americans and non-Americans abroad. However, if you ask a lot of these Bush-haters why they hate him, they don't really offer a decent, educated answer. You shouldn't hate somebody just for the sake of fitting in; you should actually know the guy and learn about the things he has done.
Kadark the Omniscient