PCs, especially historically, were compared based on technical specs. An awful lot of PCs have been sold to people who never even looked at the enclosure — only the specs. That’s not how the game is played in consumer electronics. Nobody knows what kind of CPU they have in their phones. (Where by “nobody”, I mean “no regular people”.) Apple doesn’t even publish CPU specs for iOS devices, nor publish how much RAM they contain.
With computers, again, it’s fair to say that the typical Mac costs more than the typical Windows PC. That’s not true for mobile devices, which means Apple gets to compete mostly on factors like design, user experience, and branding. In short, the nascent mobile computing market has much more in common with the traditional consumer electronics market than it does with the PC industry, and that works very much in Apple’s favor.