In the olden days, like at least 30 years ago, a gal that wanted to change the odometer reading could do it herself. The guys didn't do stuff like that very often.
Then the law rode in and said hey, STOP THAT it's not nice. So everyone thought that was a good idea, especially the guys that didn't know how to do it when they wanted to sell their used wheels.
Ahaa, it's still exists, believe it or not. Maybe Roger will back me up. It's now gone to the "specialist" mode, wherein there are roving specialists that can be called into a used car dealer to, make the appearance of the vehicle match the odometer.