“Running software you legally bought on hardware you own? What’s unethical about that?”
Apple’s operating system is a key advantage of Apple hardware. It’s clear that that Apple intends for MacOS to only run on Apple hardware. It’s in the license agreement, completely aside from copyright.
MacOS is sold at very low prices as a benefit to Mac owners. If there was a “generic hardware” version, I’m sure it’d cost much more.
“The only unethical thing here is Apple attempting to leverage copyright far beyond its original constitutional intent.”
As I said, it’s not just copyright. Most likely the DMCA could also be invoked, and whether you like it or not the DMCA is the law as well.
It’s unethical to use Apple’s software in ways Apple doesn’t allow. You buy a license to use the software, not the software itself. You should comply with the license.
The license only has force by the fact that the software is protected by copyright. How can something add additional rights beyond what is granted by copyright? Copyright exists to protect the copyrighted work, not business models surrounding the copyrighted work. Using licenses to circumvent the limits of copyright is a modern fiction designed to destroy fair use and enrich the copyright cartel. It is, simply, unconstitutional.