>With complex modern machinery, maintenance and repair is something that really matters (downtime costs money) and depending on the equipment, it is something where the manufacturer has a real edge, for example, in large industrial machinery. Not talking about some trivial upkeep here.
That's why documentation, schematics, software should be accessible by anyone who wants to fix this type of equipment. It's the difference between a mechanic going up to your farm, plug the equipment to the PC, run the diagnostic, replace part, instead of you have to call a truck, pay for the shipping of the equipment to the closest authorized dealer, and then have it looked up -> this second options costs way more time/money.
But if things are getting so complex you need to haul equipment that weight tons back to the factory, then is that complexity sustainable at all?