Phil:
You are right-and not only about JFK/LGA/EWR etc.
We are just too good to need things to be done the ICAO way. We are just too big, powerful and respected everywhere.
Our industry has grown over the decades by cutting almost every regulatory and safety corner imaginable (...and how about those airlines outside the limelight? Have you flown with guys who flew Lears, Falcons and DC6s for some of the freight operators here?), as the FAA closed its eyes to much of it.
That is the crude foundation which has created the artificially lower costs. To do things right all of sudden would upset the entire airline corporate apple cart-and the FAA Traffic Flow Control Program.