Same reason why basketball is gaining all over the world. All you need is a ball and a hoop.
Also it was mentioned that soccer isn't liked is the fact it does have ties. Well, college football up until about 15 years ago had ties and we all LOVE college football. Ivan Maisel had a pretty good column about ties in college football today
Biggest tie games in college football history - ESPN
I think that soccer fits that a lot better. Basketball needs a flat hard cement, asphalt, or wood surface and the hoops need to be a certain way and height.
Soccer just needs an open field of dirt or grass and two sticks to kick between, especially when it is kids playing by themselves.