I think that's probably the most plausible explanation. It makes me wonder what kind of g-forces the laptop is encountering. Most electronics aren't intended for "rugged" environments, and "ruggedized" equipment is a lot more expensive.
Honestly, I think this is a situation where Apple hardware is fragile instead of simply "not ruggedized". Traditionally laptops had hinge locks, for example, but the industry moved away from that because the unlocked hinges were perceived as nicer. Apple has always driven this process more than any other manufacturer. It's probably that they simply got burned here and chose a set of sensor/key/hinge designs that were a little too aggressively "thin".
