Folks make jokes about these safety devices. I would be the first to agree that some of these devices are overkill. But I have known folks that have hands sucked into corn pickers while clearing them and had their hands crushed beyond use. Pulled into PTO shafts that weren't shielded and crippled. Passed out from a medical condition fell off a tractor, ran over, and killed. A friend ran over a hidden log that flipped up and caught him in the shin. This was his clutch leg. The log pinned his leg to a fender, broke his leg, and then pushed him off the tractor. He didn't have a seat safety switch. He was just lucky enough that when the limb pushed off the tractor he fell in such a way that the rotary cutter didn't run over him. These people that got hurt were very wise men. They were not stupid or careless.