How many people do you think enter/exit JFK arrivals and departures every hour? Where are you going to land all those air vehicles? Is this a shuttle service with many seats? How do you plan for the air traffic for that many people?

About 7000 on average, but let's say 10000 since demand varies. And let's consider doing 10% of them with helicopters. If we average 3 people per helicopter, that's 170 groups in and 170 groups out. If each landing needs 5 minutes of pad time, that's 14 pads. Make it 20 to handle variation.

Wow, that makes it sound significantly more feasible than I would have guessed.

Those are all reasonable questions, but if some entity would be able to answer them, of all things, I think JFK, an airport, would be well equipped to handle them.