What's the point of "pre-order"?

Absolutely terrible.

What is the point of "pre-ordering" a device, then being told there is no stock on release date. A week later, being told a device is available, coming to the store, going through the registration process and then being told the manager doesn't have "log in's" to process the request, so I must now go to another store who might have stock so they can try again, and if not they will order a device for me...

Absolute waste of time and energy.