Punishing fear. Training discs. Scared of clicker

Something has frightened him badly either in his past life or as the result of someone demonstrating how they should ‘cure’ his barking at the hoover. They tell me this person threw spoons on the floor in front of him – or it may have been training discs specifically manufactured for ‘scaring’ a dog out of doing something.

Why would anyone think to punish fear is a good idea?