Imagine an airplane whose ceiling opened up to reveal a completely empty cabin. These planes could be parked underneath their gates at airports. At the gate itself would be the entire cabin (seats, overhead storage, etc.) as a complete unit which could be accessed by the passengers at any time before departure. At departure time, the floor of the gate opens, the cabin is lowered into the waiting plane and the ceiling of the plane closes.
I think if the boarding area contained a large vacuum chamber, and the plane cabin were heavily pressurized before docking, explosive decompression could be used to remove all passengers, or their remains, from the cabin in a fraction of a second. A similar technique could be used to load the plane.
(Most) planes use the skin as a load bearing structure to reduce weight. Punching holes in it is therefore mostly avoided, and those holes that are required (windows, door) tend to be designed to minimize stress points.
Your proposal would require a massive increase in weight (or reduction in strength/rigidity) that would most likely offset any benefit from improved loading times.
Aviation is all about trade offs. Even when I was doing systems software any benefits from software upgrades were compared to weight/power/cooling/operating costs religiously.
That would be the fastest way to load a plane.