Sure it's a security chip but why is it they didn't make it so the owner can do a one-way unlock (like Android's bootloader unlock) so people can fix their own Macs?
Because preventing repairs is one of the desirable side effect of this design.
Because even a one-way unlock can be exploited and is a vector for compromised security.
Apple has no need to prevent people from repairing their devices. They lose money on most repairs they do. What they're concerned about is their brand. If someone gets their device repaired at a shitty shop that isn't Apple certified and uses parts that aren't real Apple parts (like every screen repair kiosk in your local mall), people don't see future screen issues as issues with that repair or screen. They see a problem with an iPhone. That's what the desirable side-effect is. Apple doesn't want to prevent repairs, they want to prevent shitty repairs and security breaches.
>Because even a one-way unlock can be exploited and is a vector for compromised security.
Evidence doesn't support this at all. When was the last root exploit due to an bootloader unlock?
Towing the Apple line gets you nowhere. There is overwhelming support for companies to allow for a right of repair. Most people don't have any issues with security advances, but they do have a problem with companies using this as an excuse to further lock-in to devices that are fully paid for by consumers.
Sure it's a security chip but why is it they didn't make it so the owner can do a one-way unlock (like Android's bootloader unlock) so people can fix their own Macs?
Because preventing repairs is one of the desirable side effect of this design.