Assuming we are segmenting the Mac market from the PC market, it is much better to be in the PC market whether you are consumer or a producer. For manufacturers, it sucks to be in Apple's market if you are not Apple (PsyStar?). For consumers, they get a wider selection of products at lower price points, though they do not get the design cachet.
To make a belabored car analogy, would you rather be in the market for Italian supercars or that of the rest of the world? Both producers and consumers tend to choose the latter.