What Google did with the Chromebooks-- an interlock that zeros the manufacturer-provided root-of-trust-- is a good example of all that I want. No more, no less. Let me flip a switch and make the device "untrusted" so that I can load my own software.
I am being dogmatic. I can't think objectively about this because I have yet to see how it benefits society to absolutely remove the rights of owners to legally do what they please with their property (at least in terms of chattels).
Even with an iPhone, you have the right to flash whatever firmware you feel like. This has been upheld in US Supreme Court cases. Apple simply is under no obligation for it to be easy for you to do so. Jailbroken iPhones aren't illegal. Apple treats them as a security risk, since mechanisms for jailbreaking iPhones exploit security flaws in order to get root-level code execution. I can't say they're wrong to do so! It's no secret that they do. Or that Apple doesn't ship anything but iOS to an iPhone, or that you won't be able to install apps from outside the App Store. These are marketed as features.
Most people are interested in solving a task, and their device helps them with this. They are uninterested in general-purpose computers. And there's no shortage of them for the rest of us! Android devices are the obvious choice here, with their user-exposed flashable ROMs. (Not just the OS, but every ROM is exposed through fastboot) Or PinePhone. Or whatever Firefox is doing. You've got choices for tinkerers and general-purpose computation, it just doesn't live in a device with an apple logo.
> you have the right to flash whatever firmware you feel like... Apple simply is under no obligation for it to be easy for you to do so
This is disingenuous. Apple is not being called out for failing to create desirable functionality for iPhones. Rather Apple (et al) are being criticized for deliberately acting to purposefully constrain functionality. The first criticism would be asking manufacturers to do work to improve their products. The second criticism is telling them to stop crippling devices they sell.
I am being dogmatic. I can't think objectively about this because I have yet to see how it benefits society to absolutely remove the rights of owners to legally do what they please with their property (at least in terms of chattels).