Okay so here's the argument I've heard: if arbitrary replacements of the lid sensor were possible, it would be feasible to create a tampered sensor that failed to detect the MacBook closing, thus preventing it from entering sleep mode.

This could then be combined with some software on the machine to turn a MacBook into a difficult to detect recording device, bypassing protections such as the microphone and camera privacy alerts, since the MacBook would be closed but not sleeping.

Additionally, since the auto-locking is also tied to triggering sleep mode, it would be possible to gain access to a powered off device, switch the sensors, wait for the user to attempt to sleep mode the device, and then steal it back, completely unlocked with full access to the drive.

Are these absolutely ridiculous, James Bond-tier threat assessments? Yes, absolutely. But they're both totally feasible (and not too far off from exploits I've heard about in real life), and both are completely negated by simply serializing the lid sensor.

Should Apple include an option, buried in recoveryOS behind authentication and disk unlock steps like the option to allow downgrades and allow kernel extensions, that enables arbitrary and "unauthorized" hardware replacements like this? Yes, they really should. If implemented correctly, it would not harm the security profile of the system while still preventing the aforementioned exploits.

There are good security reasons for a lot of what Apple does. They just tend to push a little too far beyond mitigating those security issues into doing things which start to qualify as vendor lock-in.

I really wish people would start to recognize where the line should be drawn, rather than organizing into "security of the walled garden" versus "freedom of choice" groups whenever these things get brought up. You can have both! The dichotomy itself is a fiction perpetuated to defend the status quo.

The MacBook has a sensor that knows the exact angle of the screen hinge