[devmach]

Why people wants to believe it works ? Well, it has nothing to do with religion. Reason is same as using robots for manufacturing : It's cheap, fast and could be 7/24 on duty.

Why these devices haven't tested properly ? Easy, corruption (, which is not condoned by any religion)

[Houshalter]

It doesn't necessarily need to be corruption. If the device just makes random beeps or something then it's easy enough to be convinced that it's correlated with how close it is to explosives.

People do not automatically think of doing a blind test and measuring the results and seeing how well it correlates with actual bombs.