Some measures of quality are objective. In headphones, for example, one can measure the degree of distortion of the headphones in reproducing sounds. In smartphones one can measure the quality of the camera, the screen, the durability of the device, and so on.
Many of Apple's products do represent quality construction, but they extract a premium beyond even that and they often put out products which are objectively no better than the competition but which the public nevertheless swoons over and eagerly buys at a premium.
Indeed, the excess perception of quality in Apple products is such a well known phenomenon that it has a name: the Apple Reality Distortion Field. I've seen many comments in this thread alone demonstrating the truthfulness of that phenomenon.
