I don't think it's illegal in my country. Or most of the world really.

Technically it's not illegal as in criminal, but it is a violation of the contract you're agreeing to in the form of the software license. And the macOS software license only permits running macOS on Apple hardware (it can run in a VM, but the VM host must be Apple hardware).

I understand that some of these EULAs aren't enforceable everywhere, in the form of consumer protection laws inhibiting what's basically perceived to be bullying behavior. At least in the U.S. consumer protection laws are weaker, depending on the idea that when consumers are bullied, they'll spend their money elsewhere.

In a global market, asymmetric consumer protection laws aid bully behaviors. The countries were people are safe flaunting EULAs may have higher usage rates of software with unfavorable EULAs, rather than using alternatives with a more favorable EULA.

Another reason Apple is BS. "macOS software license only permits running macOS on Apple hardware", I disagree with Apple so hard here. What a scam.

They've always been this way. There was a short period of time with Mac clones, but there was still a license that said you could only run macOS on Apple hardware, or Apple licencee hardware.

I totally understand not liking the license, but if you click the agree button when installing the software on non-Apple hardware, you're basically lying.

It's against Apple licenses (for macOS and for the App Store)

Apple doesn't write laws and someone with no contract with is not bound by their rules.

If you acquired Mac OS X legally how would this be illegal? I will admit acquiring it legally could be tricky, but that is not what we were calling illegal was it?

Breach of the terms under which the OS was licensed to you. You can acquire the software legally pretty easily: buy a box in one of their retail stores.

The (mostly-untested) theory is that clicking "I agree" on the license is a legally-binding contract between you and Apple. The Mac OSX license repeatedly says that a requirement of the use of the software is that it be used on Apple-branded hardware.

So, "illegal" based on unlicensed use of copyrighted material or based on breach of contract. At least, that's how I understand the argument.

If you're a company, buy a used Mac, then. They're honestly not that expensive, especially considering all of the other stuff you have to pay for as a business.