The manufacturer wants to pull more value out of the entire lifecycle, rather than just the initial sale. From the manufacturer's perspective, they only sell t

The manufacturer wants to pull more value out of the entire lifecycle, rather than just the initial sale. From the manufacturer's perspective, they only sell the tractor once. The revenue from repairs, and second hand sales accrue to others. If a tractor lasts a long time, that is great news for repairs and re-sales, but not necessarily for people selling new models. Additionally manufacturers have to defend their brand. Letting people graft whatever no-name parts into their tractor will often result in an under-performing or dangerous piece of equipment. The idea of locked down hardware/equipment is to align these incentives, by splitting the downstream value of a long lasting tractor between the user and the vendor. Think of it like Apple. Locked down and expensive, but done intentionally to produce consistent outcomes.