Originally Posted by
MSPeconomist
The same way that old senile people who are too handicapped to board the flight and find their way to their seat without assistance remain seated in exit rows: the scanner beeps and the GA ignores it rather than paying attention.
It's called alert fatigue. Consider for a moment how many times the scanner beeps. Now think about how many times it's actually a problem.
When the scanner complains 100x as often as there is a legitimate problem, the GA is going to start ignoring it.