My understanding is that FIFA can ban countries from the organization for whatever reasons it sees fit. This probably cost the US any future world cups for the foreseeable future.
Why do you think the US cares? For FIFA, the US is the single largest source of television audience and therefore advertising revenue. For the US, on the other hand, soccer is just one of many sports. In fact, the US is one of very few countries where soccer is not the sport. Americans are nowhere near as desperate for soccer as FIFA is desperate for American money.
Are you for real? This statement is so ridiculous that I don't even know where to start. You do realize football is by a huge margin, the most popular sports on this planet, right?