It's ridiculous that we live in a world where the manufacturer is in the position to set terms of repairs. Once someone buys a piece of equipment it's theirs and they should be allowed to repair and modify it however they see fit.
Deere rose up to being one of the top equipment brands because they put extra effort into ensuring the equipment was repairable. There is a lot of equipment in the scrap heap from other brands that you can't get parts for. Theoretically you can repair them, but the cost to hire someone to recreate/design a one-off part can be extraordinarily expensive. Deere likes to boast that they have parts in stock for equipment that is 75+ years old. Hell, John Deere owns A&I Products, the premier aftermarket farm equipment parts supplier (multiple brands, Deere included). They have no problem with you repairing your equipment.
What happened, however, is that the equipment manufacturers in modern times streamlined manufacturing such that they created a whole line of equipment that is physically identical but differentiated by software unlocks. The problem is that if you were able to repair the software, you would be able to unlock features. It is access to those systems has been closely guarded to prevent piracy, just as all kinds of software has done for 50+ years. They do have a problem with you using software you didn't pay for.
