I guess we can add this to the ever-growing list of extremely expensive, complicated, inefficient and convoluted solutions to problems that end with the final specification: "but it can't be a train".
Yeah because I want to haul all my luggage on a train journey when I go to the airport. I’ll take a train to a lot of places but the airport is not one of them.
Yes, let's depend on a train for my time-sensitive journey with lots of awkward luggage.
Do you people even ride trains? Are you OK with the 50/50 odds of gettings home on time?
My company used to cover a car service for us (limo), my door to the terminal.
When they set up the AirTrain, I stopped using the car service. It took longer, but I have always had a soft spot for mass transit, and I kind of got a kick out of boarding a train in Huntington, NY, and leaving the train, in Shinagawa.