Then why don't they? As said before, F1 desperately needs a good American driver - it could boost up their business by billions but all American F1 drivers in the last 15 years or so have just plain sucked...
Probably because they were born in the States and F1 has a very small presence here
. From what i know most Americans that go to F1 have the deck stacked, they usually aren't given the primo rides and crews, and are generally treated with disdain. F1 is quite snobbish and parochial.
Same with Montoya here, He has a 2nd tier ride and it reflects in his placings. If he had Kyle Busch's ride he'd magically get a lot better.