The cause of the dismissal is said to be rooted in market definitions. Psystar has argued that the Mac OS is not easily interchangeable with other operating systems, and as such, can be qualified as its own unique market space. By contrast, Apple has argued that a single brand cannot possibly represent its own market, whether legally or factually. Alsup suggests that while a brand can indeed represent its own market, boundaries within antitrust law are determined by "whether consumers view those [debated] products as reasonable substitutes for each other and would switch among them in response to changes in relative prices."

Psystar's real problem, says Alsup, is that it has failed to adequately distinguish the Mac OS from its competitors. The judge in fact claims that Psystar has undermined its arguments, mainly by suggesting that the Mac OS performs functions similar to other software. "The counterclaim admits that market studies indicate that, although Apple computers with Mac OS enjoy strong brand recognition and loyalty, they are not wholly lacking in competition," Alsup writes.

Also cited is Psystar's reference to Apple advertising. Alsup observes that a company would be unlikely to market as heavily as Apple if it did not have competition; Apple is further said to have made it clear that the Mac OS is locked to first-party hardware, meaning that customers cannot be accidentally trapped in the Mac ecosystem.

Along with antitrust allegations, Alsup has dismissed other counterclaims connected to the Cartwright Act, the California Business and Professions Code and unfair competition.