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.
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.
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?
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.
Seriously, I can never take this argument seriously.
I can easily develop iOS software without owning an Apple computer...but I can't do it legally. I'm happy I'm not in mobile dev, and this is one reason.
Almost entirely avoided still means you have to go out and buy a Mac and keep Xcode running on it.