As someone that owns several Deere tractors, there are no restrictions on mechanical repairs, I can buy parts all day long to do everything up to and including replacing every one of the 20,000 parts on a tractor.
I don’t know what people are pointing to as not being able to repair, but I’ve never encountered it. Maybe flashing a custom firmware on the ECM? But why the hell would I want to do that, except to blow the engine up when I need the damn thing?