I am right now sitting in a Pendolino train, not far from Prague :) Pendolino is a nice technology, but expensive to maintain. And aircraft, unlike trains, is

I am right now sitting in a Pendolino train, not far from Prague :) Pendolino is a nice technology, but expensive to maintain. And aircraft, unlike trains, is very sensitive to total weight; the actuators for the seats will be extra dead weight that you need to lift, and this extra weight may eat quite a bit of the fuel savings, if not all of them.