There's that angle, yeah, but it's the creation of a single point of failure that I was thinking about. And not even in all that tech-centric a way.
My hometown used to make a sizable chunk of the US's fasteners, and there was real concern during the Cold War that dropping a single bomb on it could cripple the entire nation's industrial capacity. Here, it seems like there may be an unacceptable strategic risk that a bomb dropped on Moline, Illinois could cripple the entire nation's food production capacity.
But then it will not be a problem of business greed and stupidity... it will become a "national security threat", which will require more taxpayer money to solve, and of course may lead us closer to a war with whatever countries remain to be invaded by this immoral government. And "poor" JD will be just a victim of this vile threat "against us all".
What if the server rack is in the farmers house and not connected to the internet? Deere could just send a regional technician as needed to patch or troubleshoot. They probably already send regional salesmen to farmers regularly, what's another seat in the car?