There are lots of evil things that proprietary software companies might do. Companies put their own profit above the rights and freedoms of their users, and to that end, much can be done that subjugates users. Even as someone who avoids proprietary software, I still read many proprietary license agreements (mainly to see how bad they are). I've certainly become numb to the constant barrage of horrible restrictions they place on users. But, sometimes, proprietary licenses go so far that I'm taken aback by their gratuitous cruelty.
Apple's licenses are probably the easiest example of proprietary licensing terms that are well beyond reasonableness. Of course, Apple's licenses do the usual things like forbidding users from copying, modifying, sharing, and reverse engineering the software. But even worse, Apple also forbid users from running Apple software on any hardware that is not produced by Apple.
The decoupling of one's hardware vendor from one's software vendor was a great innovation brought about by the PC revolution, in which, ironically, Apple played a role. Computing history has shown us that when your software vendor also controls your hardware, you can easily be “locked in“ in ways that make mundane proprietary software licenses seem almost nonthreatening.
Indeed, Apple has such a good hype machine that they even have convinced some users this restrictive policy makes computing better. In this worldview, the paternalistic vendor will use its proprietary controls over as many pieces of the technology as possible to keep the infantile users from doing something that's “just bad for them”. The tyrannical MCP of Tron comes quickly to my mind.
I'm amazed that so many otherwise Free Software supporters are quite happy using OSX and buying Apple products, given these kinds of utterly unacceptable policies. The scariest part, though, is that this practice isn't confined to Apple. I've been recently reminded that other companies, such as IBM, do exactly the same thing. As a Free Software advocate, I'm critical of any company that uses their control of a proprietary software license to demand that users run that software only on the original company's hardware as well. The production and distribution of mundane proprietary software is bad enough. It's unfortunate that companies like Apple and IBM are going the extra mile to treat users even worse.