The macbook pros are quite durable to scratches and scuffs, so perhaps they could have used the same material/processes. Not sure about the iPhone 5 since I haven't handled one in person yet.
They do. On the white/silver iphone5. And it, by all accounts, handles wear just like the unibody macbooks. The issue only relates to the black/graphite iPhone5, due the coating used to make it appear black/graphite.
The iPhone had a metal back that exposed a black sub-surface with wear - and people complained. The iPhone 3G/3GS had a plastic back that scratched, chipped, cracked and was known to develop discolored stress marks - and people complained. The iPhone 4/4S had a glass back that chipped, scratched and shattered - and people complained.
I'm not sure about the Nexus One, having never seen one. But I am fairly certain that no matter what Apple makes a phone with, they can not ship anything that's literally perfect. And they will ship millions, with the initial sales tilted toward obsessives and perfectionists. These people have always found things to complain about and they will always find things to complain about.
Further, the press knows Apple articles are an eyeball gold mine, particularly Apple articles about a controversy, so they will always make as big a deal out of anything that they can.
See also: the 'yellow' screen glue issues; 'antennagate'; the possibility that repeated application and removal of cases to an iPhone4/4S might cause cracks; the stress cracks on the 3G; wear on the silver face band around the 3G/3GS; wear on the original iPhone back; dead pixels on the 4; etc.
I've owned a unibody MBP for only a year or so and it has several visible scratches, especially on the underside. It doesn't bother me, at least not as much as a case would, but based on my own experience I definitely wouldn't say "quite durable." I also wouldn't prefer any other material.
The verdict: I couldn't care less. It's a phone and after putting the battery back in and the cover on, it never ceased to work, it didn't even change my user experience in any way (broken glass, buttons etc.)
I would not buy a phone that requires me to put in in an ugly case, but I would also not care much about a few scratches here and there as long as the phone doesn't break.
So if you buy a phone partially for it's supposedly amazing design and then hide it inside those ugly rubber casings or whine about small scratches, well, than you lost me along the way.