Because gaming consoles are for a very specific purpose (and sold as such – the ruling against Sony for blocking Linux on the PS3 only happened because they advertised Linux compatibility) and Macs are general purpose computers

And PS3 had Linux support because of EU taxes :)

Game consoles had a higher import tax than "computers" -> allow linux, save money.

IIRC they did a similar thing with the PS2 with some janky-ass BASIC interpreter being available.

No Universal Machine inside any consumer product should "be for a very specific purpose," where it is locked down to prevent the consumer-owner from making software or firmware modifications to it. This goes for pacemakers, automobiles, microwave ovens, MRI machines, and even Intel IME or the little microcontroller on your NVME drive. If I were elected Benevolent Dictator For Life of the United States, I would immediately withdraw us from WIPO, strike down the DMCA, and implement a 100%+ sales tax on all "finished products" for sale which had even just one such Universal Machine in it locked down as described, AND mandate a minimum of 25 years full warranty and support on such products with forced 100% buy-back for failure to support or patch or open. We must relegate today's form of 'proprietary' to a rental/lease-only model and quit calling it 'ownership'.

We must demand hardware which strongly adheres to the GNU/FSF ethos or it must be rejected society-wide (or made too expensive for the average normie to afford, effectively killing its market). Universal Machines are to free humanity, not limit or enslave us! THIS is why I don't buy Apple and hold my nose buying x86 (Qubes OS) and Google Pixels (GrapheneOS); if I could afford Raptor Engineering's TALOS II, I would own only that!

Macs are special purpose hardware for running macOS. A PC you build from custom components in your office is a general purpose machine. The gaming console example by oc is quite apt.

Macs are specialized in running macOS and its app ecosystem and integrating with other Apple devices. Apple don't advertise Linux compatibility.

So what you're saying is it would be acceptable for Microsoft and PC manufacturers to lock down their hardware to running Windows only? Most ship with Windows so why not?

Yes? That's what the law currently allows. If we want to make a law that says companies are required to let end users install _any_ software they want onto any device they legally own, that encompasses almost the entire consumer product ecosystem. It is becomes hard to determine what is "general purpose" and what happens if Acer says "this machine runs windows specifically and isn't general purpose?" or they say "you no longer own this machine, you are licensing the hardware from us?"

It would not be acceptable, and it is the duty of ethical whitehat hackers to break such digital locks, flip the bird to Congress and the WIPO's DMCA, and free humanity. It would be ethical to form militias and raid federal prisons to free whitehat victims caught up by the state for it. Liberty is not free.