Obviously a lot of people do hate America, but that depends on what their idea of "America" is.
If you're a Mexican just barely over the boarder who realizes that you can get more money and safety by sneaking in, you'll have at least a somewhat good idea of America.
If you live in the Middle East and the only "America" you've seen are the soldiers patrolling the streets that your Islamic Extremist peers tell you are infidels, you're going to dislike America.
Of course there are also those who say "I hate America" really meaning "I hate Bush" or "I hate America's current foreign policies" etc. I don't particularly like or dislike "America" but regardless of my feelings toward it I guess I'll have to deal