> If John Deere values it more than farmers, then they will sell tractors that farmers can't repair on their own, hoping to earn more on repairs rather than easier to repair tractors that are more expensive up front. Basic market economy.

It isn't possible for that to happen without one of your other concerns also being true, because the profits from preventing repairs come from the customers. So it's at best zero sum and in practice it's negative sum, because the manufacturer isn't always the most efficient party to do the repair, e.g. because the farmer who is already on site and does it themselves can get the equipment back in service faster than waiting for the company's mechanic to arrive.

Meanwhile in cases where the manufacturer is the most efficient party to do the repair, the customer could still use them even if nothing forced them to. So the fact of it happening is by itself proof of this:

> It only needs to be litigated when there is a threat to the market itself (ex: monopolies)

Moreover, notice that this keeps happening with tech products. Since customers don't like it, you would expect a competitor to show up and make the exact same product but without the locks, so why don't we see that? The answer, of course, is copyright, a government-granted monopoly. The law prohibits a competitor from copying their design/code. So there's your monopoly.

But copyright is only meant to prevent the competitor from making a direct copy of their software and competing with them in the market for the original product. They're only supposed to have that monopoly. Leveraging that to monopolize the separate market for repairs is monopoly abuse, and applies equally to every company selling a product covered by a patent or copyright monopoly.