But external is the problem. External devices are fine for your desk, but are a PiTA when travelling. I'm imagining using the external drive attached to my Mac on my lap in the car or on a plane. That's just plain inconvenient.
Their external drive is so small/thin and light that you won't notice it at all when travelling. If you need something off a DVD or CD for a plane trip and don't want to pull out the drive, then put it all on a thumb drive for the plane trip.
They aren't going backwards to a drive that no one is using anymore.