Apple's primary business is to sell hardware, always has been. The fact that the are willing to sell a new copy of their superior (yeah, I said it) OS to their existing client base, people that own Apple hardware, thereby allowing them an upgrade path (hardware specification willing) to the latest OS. I'm sure it's seen as a "value-add" or at least a way to open a revenue stream from a customer that has already made a significant purchase and may or may-not be likely to spend money on a new machine when their old one will run the latest OS to what is possibly (to them) an acceptable level.
I'm thankful they originally designed their OS to run on their hardware. If not, who else would have done it? Microsoft? Xerox? Remember back then it was almost inconceivable that anyone would actually want a home computer.
Apple spoke out about DRM on music because there is no need to encrypt data (AAC or MP3 format) that is readily available in the clear (AIFF or WAV files on an audio CD).
I agree that as it applies to media, DRM is bad. And if you buy a copy of Mac OS you, if you can, should be able to install it on your toaster if you want to -- just don't expect Apple to support it.
I'm sure the HDCP thing, sucky as it is, is a foreshadow of the shape of things to come until the content distributors pull their heads out of their asses and realize that customers do not want. And that their paid product is inferior to the one that anybody with a little initiative can download for free.
The fact of the matter is that an Intel Mac offers you the _most_ choices of supported OS'es out there, bar none.