And Bootcamp is nothing more than smoke and mirrors, a checkbox to tick in order for apologists to have amo.
Having used Windows on a MacBook Pro 2016 for two years, my experience has been worse than with a commodity Levono at 1/4 the price.
Given that you were running Windows on your Mac, I gather that your argument is more one related to the licensing issues of running macOS on non-Apple hardware, rather than an argument that it isn't technically possible. In any case, there is this. Curious how the project will be impacted by these new changes. From the article, it seems that in No Security mode the bootloader may be modifiable in the ways that it needs to be for modifications like Clover to work.
Clover EFI bootloader https://sourceforge.net/projects/cloverefiboot/
Features
Boot OS X, Windows, and Linux in UEFI or legacy mode on Mac or PC with UEFI or BIOS firmware
Boot using UEFI firmware directly or CloverEFI UEFI firmware emulation
However, could you elaborate on why the fact that you cannot buy an OSX license proves your point that Apple is in the business of selling licenses? I am at loss.
Ahhm. BootCamp[0] is an integral part of MacOS for a while. (and before that, for a couple of years, it was a free add-on). It is the apple mandated, supported, sanctioned way to run Windows on a Mac, including needed drivers. Battery life is not quite as good, true.
Your claim that "Apple is definitely not in the hardware business. What they sell is licenses." is contradicted, both by the existence of BootCamp, and by your inability to buy a license without the hardware (and/or at a price that does not include a profit premium on that hardware).
[0] https://support.apple.com/boot-camp