They are not innately bad, but they are implemented in a bad way. A system of hydraulic control lines cannot be locked behind copyright. They can be physically fixed. A cracked manifold can be welded or replaced. But when fixing a modern electronic system you must have the permission of the manufacturer before replacing a part, or even opening some boxes. Any mechanic can see leaking hydraulic fluid. But modern electronic systems can require special/expensive tools just to read the error code telling you which part has failed.

Next up: John Deere invents a hydraulic rights managment (HRM) system that implements a communication protocol between hydraulic components using high frequency pressure changes in the hydraulic lines. These signals are interpreted by mechanical/hydraulic processing units to p̵r̵e̵v̵e̵n̵t̵ ̵t̵a̵m̵p̵e̵r̵i̵n̵g̵ ̵w̵i̵t̵h̵ ensure the quality of the product.

Don’t give them ideas. They have proven themselves willing to screw their customers. Don’t give them another way to extort us.