If you are developing an AI sophisticated enough to pilot a tractor, would it only be able to drive one model? If John Deere ever achieved this goal, the AI should be adaptable to other brands as well.

Car manufacturers are doing this already with Android. They do not develop the OS, they simple accommodate their cars for it.

I have a working GPS system that belonged to my father's John Deere tractor. I cannot use it anymore, even in other John Deere tractors. This is wasteful and makes no sense. People working in farms, close to nature and subject to profit margins they do not completely control feel very uncomfortable with this.