Fuel Economizing as New Risk

Is fuel conservation a a new source of risk? I have twice recently been on planes that had to turn around after long taxis/queuing to go back to the ramp for more fuel, and then this story today about a San Diego-bound Amtrak train that ran out of fuel. Amtrak is running things a little more tight wrt fuel fill-ups, as are most major U.S. airplanes.

Relatedly, here is Amtrak bragging about being more fuel stringent.