Here is the thing. F1 is a business, and at the tip top is a massive shark. You may know him as Mr. Bernie Ecclestone.
The pursuit of a lasting US GP is to tap the money pit that is the US Market. With the US would come marketing, branding, car sales via manufacturer deals and promotions. All of the teams want in on it, but to really understand it you have to separate the sport we all love from the business that runs it behind the scenes.