Yup. Whenever you see a “don’t do XYZ,” it’s because some did it.

A perfect example of this just happened to a guy I know. He uses these machines at work. He was training a new guy and explicitly said, “there’s no guard here, but make sure your fingers don’t go in. This thing’ll pull them right off.” A few days later, the guy know accidentally got a finger in there and was just barely able to save it. He got incredibly lucky and easily could’ve lost a whole hand. And now they finally decided to pay someone to put guards on those specific machines to prevent it.