They are doing it to protect the millions that they've invested into the autonomous driving software. Imagine this scenario, deep inside of a random 3rd-party

They are doing it to protect the millions that they've invested into the autonomous driving software. Imagine this scenario, deep inside of a random 3rd-party firmware was an obscure piece of code that allowed complete remote control of the tractor. Several remote killdozers is what you would then have to deal with. With access to the ECU(s) the hackers could even disable John Deere and the farmers control of the tractor. Even a small bug would result in huge damage or loss-of-life. Google and Tesla will for sure not allow access to their proprietary firmware / system code. Just think about installing a custom Android ROM on a device with a very small community and then imagine that on a car or a tractor. Stick with stock John Deere firmware and purchase from a competitor if you don't agree with their policies. I remember this story from a couple of years ago. I was impressed that farmers are some of the first people to use autonomous vehicles and drones to manage and watch crops. Amazing times we live in.