This is unethical, basically he calls for jumping off of flights at layovers, which violates the terms of the ticket. There's even a security issue for the airlines, because they need to check if your bags are flying unaccompanied. Ironic that the NYT cracks down on people evading its paywall but is selling content on doing the same for air travel.
This guy was modded down, but are there ethical issues? If I'm booked through from SFO to DFW to MIA and I vanish at DFW, they're going to be calling my name over the PA system and trying to figure out whether or not to hold the DFW-MIA flight. This is especially true if my SFO-DFW leg is delayed -- my vanishing act might well wind up holding up a planeload of people as the airline figures out what the hell has happe…
Now there is no reason to delay the flight.