i wouldn't say hate...... i would say not popular enough to become a mainstream sporting event.... (yet)
i played it until i was about 9 yrs old, after that i got into American football and never looked back.
Americans dont have football/soccer, like Socia said it's just not as prevalent. I used to play it too, and I thought it was a lot of fun. Its big in high schools around the country too, we just dont have a big national group for it.
I'm not from America, but from what i see Football is considered in elementary and high school throughout the states. The problem is that it isn't a big career for an American since there aren't quality trainers there that could get them into big European teams. This is why Donovan left the US league to go to Barclays.