The truth of the matter is, they like CDs. They like using CDs.
Most people marvel at the technology.
Little ones and zeros zooming large into this and that. But most importantly a CD represents a higher grade of quality including whatever lies in its contents. CDs carry impact. A seriousness that artists need to get a listener's attention. Granted, most people don't need to be convinced, but if there's still any doubt then conduct an experiment using your own original material.