I hate that you're getting downvoted for this, understanding the other sides argument is how you can evaluate the truth. It's important especially when the issue is clear cut like this

The argument John Deere made in this case is basically "we have to put DRM in [blocking repairs from anyone not licensed by us] because of EPA regulations on emissions". The EPA rules clearly state all the necessary emissions information for motor vehicles be made available; one of their arguments on all sorts of regulations has long been "tractors aren't motor vehicles". This is a legalese argument to be sure though.

More broadly, their argument has been: we need this control, otherwise users or repairmen might do something improper and make our equipment unsafe. They've also argued this might unfairly expose them to liability

Of course, the counter argument is: yeah, that's how everything has always worked. If they deliver you a faulty product based on negligence, it's on them. If you or your mechanic modify your car, plane, computer, etc. dangerously and it explodes, it's not the manufacturers fault.

What it really comes down to is rent seeking. Selling a product with a limited need means you have a limited market. It's what happened to instapot - they made a solid, reliable product, they dominated the market for pressure cookers. Then they went bankrupt because their income started to crash as the people who wanted one and didn't have one dwindled. (I'd say job well done, they made a good product and now it's everywhere, now they should downsize to the point where they reach equilibrium with current demands)

100 years ago, pretty much all markets were growing as 3rd world countries industrialized... Now there's basically nowhere on Earth willing or able to become new consumers. Companies don't care about cash - they care about cash flows.

If you can't make a way better tractor every few years, you either need to make them not last for long so they keep coming back for replacements or repairs, or you try to turn ownership of their products into a service

You want an argument in favor of not letting consumers repair things they've purchased?

I'll take this at face value and assume u are asking "why is the EPA involved in this and why did they need to do anything, why is the world stupid"

The answer is that corporations who sell vehicles want more profit (obviously) and so they decided to interpret a clause in the Clean Air Act, which says, "vehicles must be repaired to follow the Act" to mean that, "vehicles must be repaired [by the parent company] to follow the Act [because consumers cannot be trusted to do so themselves]"

So the EPA issued a letter saying "corporations you're totally fucking wrong and being assholes, this is NOT the intent of the law. it just says the Clean Air Act can't have a 'haha i repaired it lol' loophole"

Are you testing my knowledge or are you just ignorant? Almost all companies involved in manufacturing have been making items more disposable or harder to repair for years (see phone, cars, computers, TV's and almost everything else you can buy) to encourage people to buy new and bring the profits back to base.

A farm equipment company can't afford to be known for disposable equipment. Instead, they tried to make it impossible to work on the equipment without special computer equipment, so you'd have to book a technician to do something as simple as an oil change.