Customers are really that stupid.
I worked at a company that did contract work for an American auto manufacturer, back in the day of 5-1/4 inch floppy disks. A day after installing a new computer-controlled NC machine in their engineering department, the customer called and said that the machine would not boot after the first shift. When I got there, I determined that the boot floppy had become corrupted, so after thoroughly checking out the floppy drive, I created another boot disk. After watching the user run it through a few boot cycles, I went back to the shop.
The next day, same call, same problem, same solution plus a new floppy drive.
On the third day, I had to go back again. This time, my supervisor, his supervisor, and the sales rep all met with the NC operator, his supervisor, his supervisor, and some doofus from their legal department, who said that if the machine wasn't working by the end of the day, the entire contract would be cancelled. I went through the same routine as the previous two days. Then the operator took over, swapped disks, and ran the machine through its paces.
"Everything looks good", he says.
"Anything else?" I ask.
"Nope! I got it!"
Then he picks up the boot disk, holds it against a nearby file cabinet, and fixes it firmly in place with a 5-ounce magnet.
30 minutes later, they had a new boot disk, a second floppy drive for the operations disk, and a new operator for the NC machine.
No wonder the American automobile industry went into a decline for the next 30 years ...