Clean-looking surfaces acquire subtle fingerprints, then obvious fingerprints, then thin and surprisingly-hard-to-dislodge little dark films or crusts of finger oil. If you virtuously soak a paper cloth in Windex or Mr. Clean or 3M Desk and Office Cleaner or isopropyl alcohol, you discover previously-unnoticed little bezels and grooves and things that are suddenly revealed as telltale dark-brown lines of uneven weight.
That plastic cling-wrap stuff protects the little LCD screen and control panel of that little portable device during shipping, and then the moment you peel it off the surface underneath start to accumulate scratches. (Or if you leave it on, little bubbles form underneath).
I'm tempted to single out Apple as a particularly bad offender, but it's not really true. It just seems worse because a) Apple gear looks better to begin with, and b) it feels like more of a betrayal because Apple gear gives the impression that they did not "cheap out" on the enclosure.
Now, spare me the obvious "planned-obsolescence" explanation. Sure, that's part of it. But they can't really expect you to buy a new computer every six months. If it were planned obsolescence, they'd design the computer that looks brand spankin'-new for exactly three years and then suddenly and swiftly deteriorate into crud... like Dorian Gray.
Seriously... If They Can Put A Man On The Moon... and increase the speed and storage capacity of everything to the point where we need to learn a new SI prefix every few years, why can't they design enclosures that look good for more than a few months? That resist finger-soil and scratching? That don't accumulate cat hairs and lint between the keyboard keys?"