Taking the automotive analogy to the extreme, PCs (Macs and Windows and Linux machines) are now entering the phase where the components are now almost identical. This leads to the situation where manufacturers have several models at various price points in their product lines and the only way to differentiate them from the competition is by the bells and whistles you offer.
So Dell, HP, Sony, et al. sell the PC equivalent of Chevys, Fords, Hondas, Toyotas, and Nissans. They also sell Cadilacs, Lincolns, Acuras, Lexuses (Lexi?), and Infinitis.
Apple is more like BMW or Mercedes - their selling point (really) is their design and the statement they make (I have a BMW). The top-of-the-line models (e.g. BMW 8-series) are competitve spec-wise with competitors' products, but the low-end models (3-series, C Class) are significantly overpriced for their specs, but have bells and whistles and styling that attract a certain segment of the market. You'll never capture a large market segment, but you will be able to operate with a higher margin on the market you do have.
The PC market is a little more homogeneous - the CPU (the engine) is basically the same for everyone now. So styling as a way to differentiate your product is paramount. Because Apple's big difference is the OS, they need to play it up as much as they can and put all the bells and whistles on it that they can.