I used to write POs for >$1MM worth of Apple equipment/year and spent hundreds of hours dealing with their service centers. The argument that allowing total monopolization of the repair process "maintains system integrity" isn't supported by the actual service experience.
It should not surprise anyone that a company that arrogates the right to sue competing service centers and thus need not fear any competition does not perform as though its customers might choose to take their business elsewhere.
There is literally no corporation on Earth that couldn't make this argument: "Why should we let farmers fix their tractors? How can we maintain their integrity unless we get a monopoly? Do you know how important the food supply is?"
"Let someone else fix your toaster? You ever hear of kitchen fires?"
"Food-borne illnesses kill more people than all the wars combined: why should third parties be allowed to service your dishwasher?"
"Food-borne illnesses kill more people than all the wars combined: why should third parties be allowed to service your dishwasher?"
"How could we ever hope to calibrate your car's air-pressure sensors if you're allowed to choose any tires and any garage to install them?"
"BadUSB is an unstoppable attack: why should our device recognize ANY USB devices unless we sell them to you?"
"BadUSB is an unstoppable attack: why should our device recognize ANY USB devices unless we sell them to you?"
"Operating an ISP is incredibly hard: why should you be allowed to choose which websites and services you offer? How can we guarantee service to our OTHER customers if you're allowed to choose third-party websites we haven't vetted?"
Apple isn't the first company to make this argument. AT&T sued anyone that created ANYTHING that could plug into the phone network ("No company has ever built a network this sophisticated, it is critical to national functioning, and we are the sole authority on this")
This culminated with AT&T shutting down a company that made a PLASTIC CUP that fit over the receiver to block outside noise. This was so obnoxious that the courts shut down the racket (finally). en.wikipedia.org/wiki/Hush-A-Ph… 
Of course, this led to all kinds of crazy stuff! For example, this dickhead made devices that let you steal long-distance calls and sold them door-to-door in his dorm: todayifoundout.com/index.php/2012…
And of course, every pirate wants to be an admiral. When Jobs was plugging shit into the phone network that allowed his customers to do things that benefited them at the expense of AT&T's shareholders, that was "progress." When third parties fix Iphones, that's "piracy."
There's nothing especially evil about the self-delusion that leads a corporation to evince a rule that it routinely violates, but only for OTHER PEOPLE, because the corporation is a "good actor" and they are "bad actors."
What IS especially foolish and remarkable is for corporations to create personality cults that lead their customers to view this hypocrisy as legitimate
...and to denigrate other customers who want the right to arrange their affairs to their own benefit, even if it is suboptimal for the shareholders as "using the product wrong" and to say absurd things like "Why did you buy it if you didn't want to obey the corporation's edicts?"
Because the reason to buy something is to make it your property, and then use as you see fit, to your benefit, even when this is not how a corporation feels you should use it.
Or, as they used to say: to "Think Different"
