I bet most guys don't shoot enough to have their scope shoot loose if they mounted it with any amount of common sense. The "phenomenon" likey occurs with guys who actually get out there and shoot the piss out of their guns, and don't degrease, lock tight, and torque.
I has a scope ring come loose on an AR this winter, it happens.
I also for what it's worth used to have a Savage 110 .270 that the front action screw was too long you could only make it "finger tight" otherwise it would bottom out on the action and bind the bolt. At the time I didn't know any better and still shot the gun like that. It never shot under an inch at 100.