> This unique type of U.S. transportation has no commonly-recognized name, and I will soon arbitrarily assign a term for them just to make everything easier.

They're a kind of tram. I suspect the author is from New York, because the train-to-the-train of which he speaks largely doesn't exist in any other city in the US, and the concept of a two-car light rail-esque system seems astonishingly foreign to him. Especially because the tram style of light rail is quite rare in the US but rather more common in Europe.

> The train itself should just go to the airport, like they do in virtually every other airport with a mass transit connection in the world.

Let's look at cities in the US that have a large airport and a metrorail mass transit system:

* NYC, LaGuardia: accessible only by bus

* NYC, JFK: Tram system (electrified 3rd rail) that connects to two subway lines.

* NYC, Newark: Monorail that connects to commuter rail station

* DC, DCA: Metro stops literally between the parking garage and the airport terminals.

* DC, Dulles: Metro stops literally between the parking garage and the main airport terminal (although there is a very large surface lot between the two).

* Chicago, Midway: L stops literally at the terminal.

* Chicago, O'Hare: L stops in the middle of the three main terminals.

* Boston: T stop is roughly as far away as economy parking. No internal circulation over than buses.

* San Francisco, SFO: BART stops at the airport terminals (although it does a funny Y setup to get in there).

* San Francisco, Oakland: BART station is some distance from the Oakland airport. The tramline connecting them is a rubber-tired tram owned and operated by BART.

* Philadelphia: SEPTA has a connection to the airport that is a commuter rail connection, with stations at several terminals.

* Atlanta: MARTA stops literally at the airport terminal, in fact closer than the tram line stop to the rental car facility.

* LA: Metro does not have a particularly close stop to LAX. No tram-like system at LAX.

* Miami: Metro stop is at the rental car facility, terminal itself accessed via tram-like system.

* Baltimore: Light rail stop at the terminal itself. (No connection between the heavy rail at Baltimore and the airport).

* Cleveland: Metro stop at the airport terminal itself.

In summary, of 16 airports considered here, 4 have the pattern the author decries, 9 have rail transit stops directly baked into the terminal entries, and 3 do not have either pattern. Functionally speaking, the Oakland and JFK systems are effectively mass transit spurs not built to the same technology as the main mass transit system and having little other destination than the airport, neither of which it turns out are particularly uncommon (since airports tend to be massive tracts of land far removed from anything else, it's often uneconomical to extend regular mass transit all the way to the airport).

(There are basically two competing proposals to bring transit to LaGuardia. One would extend the N/W from Ditmars to the airport, the other would be an AirTrain-like system that extends to the 7/LIRR at Mets/Willet Point and is sometimes suggested to connect all the way to the existing AirTrain at Jamaica. Guess which one is moving forward.)