As explained in Lockergnome’s post Are Hackintosh Computers Legal? (video below), when you “buy” OS X software from Apple, you are subject to the terms of Apple’s end-user license agreement (EULA). The EULA provides, first, that you don’t “buy” the software—you only “license” it. And that the license terms do not permit you to install the software on non-Apple hardware. Thus, if you install OS X on a non-Apple machine—making a “Hackintosh”—you are in breach of contract and also copyright law. Thus, for hackintoshers: “Apple can bring causes of action for breach of contract, copyright infringement, violations of the Digital Millennium Copyright Act [DMCA], etc. and no one is going to want to spend the hundreds of thousands of dollars it would take to get to a jury.”
This is what you get when you have copyright law. Without copyright law not only would you not have the copyright-DMCA “teeth” to add strength to a sort of license-contract claim–so that the terms of Apple’s EULA could be enforced merely as contract claims, not as copyright infringement—but the terms of the EULA would not apply to people using pirated copies of Apple’s OS software. Imagine: Apple sells a copy of (well, licenses) OS X to person A, and restricts A from putting OS X on a non-Apple computer, by the EULA. A then leaks a copy onto some pirate site. Third parties B, C, D, etc., now copy and use and further distribute copies of OS X. These third parties never agreed to any contract with Apple, so they would not be in contract breach if they were to put OS X onto a non-Apple machine.
Which means: random person R would rather get a pirated copy than a copy from Apple–not only would it be cheaper, but it would come with less possible contract-breach liabilities.
Knowing this reality, Apple would be reluctant to impose such ridiculous terms in its EULA in the first place. They would not want to drive away potential customers and push them towards pirated copies. It would most likely simply sell the software (not merely “license” it) to users for a fair price, with no draconian conditions like “you may not use this on a non-Apple computer.”