Your car, heater, air fryer, and lawn mower are consumer devices. If you modify them and they become unsafe, you're at fault.
However, farm equipment is classified as industrial equipment and if you can modify it to be unsafe without being an expert in that domain, then it is the manufacturers fault that you can do that.
Locking down industrial equipment so that it requires a trained technician to modify it is one of the ways that industrial equipment manufacturers try to mitigate the liability that they face.
> then it is the manufacturers fault that you can do that.
This is not always the case, and if it gets to the point that legislation has to be written to stop you, it's likely you don't care that much about the law in the first place.
When Marvin Heemeyer built the Killdozer, nobody blamed Komatsu for providing him the parts. Unprecedented, violent problems can happen with all sorts of equipment. We stop these accidents by holding professionals liable, not their machines.
The legislation and liability for industrial and agricultural equipment already exists. Under that structure, the manufacturer is the one facing the product liability claims if any claims are to be paid out.
If you (the framer) modify a JD tractor and someone gets hurt, JD is is the one likely to pay.
However, farm equipment is classified as industrial equipment and if you can modify it to be unsafe without being an expert in that domain, then it is the manufacturers fault that you can do that.
Locking down industrial equipment so that it requires a trained technician to modify it is one of the ways that industrial equipment manufacturers try to mitigate the liability that they face.