You're dismissing most of Europe, much of Asia, Austrailia, and much of North and South America where soccer is played and beloved in decidedly non-third-world places. The hatred is rooted in insecurity. Soccer will always be the world's sport. The NFL can never dream to achieve that status. It will never happen.
I've been living in Australia for a couple years now and soccer is nowhere near as popular as the two rugby leagues and Australian Rules Football. I've met as many or people interested in NFL here as soccer (though I wouldn't necessarily say that's true for all of Australia, haven't been all over the entire continent...) Most of the soccer fans here are European transplants, whereas a lot of the NFL fans (or NFL-interested, if "fan" is a bit too strong of a word to describe them) are Australians who are interested in sports similar to their own.
As a disclaimer, I don't care for soccer at all. Never been interested, not when I lived in an Asian country for a couple of years where it was the dominant sport, not now, not ever. But I don't hate it, soccer players are certainly in better overall shape than football players. It just isn't as exciting a game to watch, not as complex and teamwork focused.
I agree with the previous poster about the reason for its popularity. It certainly seems to be rooted in the accessibility (all you need is a ball, and people from poorer countries will choose the obviously economical choice) and the effect of British (and European) colonialism. Most of these countries where soccer is the dominant sport were colonized by England, the Netherlands, Spain or France. The effects of that time spent under European rule continues to be very clear today, and soccer is a big example of that.
And much of Asia, South America and plenty of Europe are
third world countries. You mention North America, but the only part of North America where soccer is popular is Mexico...which is as close as North America gets to third world..
The spread of basketball is also testament to the "accessibility" reason. Basketball is becoming a very international sport too, and it's because all you need is a ball and a hoop.
In summary, soccer is not the dominant world sport because it is a superior sport...that's just ludicrous. The 3 main Australian sports are clearly superior to soccer in every way, combining the cardiovascular rigor and finesse of soccer with the physicality of NFL. I still prefer NFL, myself, by a large margin because A ) it's what I grew up liking, and B ) the rugbys and AFL still don't have the complexity and teamwork heavy nature of NFL.