I'm not sure how the owner has kept the phone (it was a picture on another forum) but I do agree with you, it doesn't look like he was taking much care of it at all.
I'm the same as yourself - I never put it in the same pocket as my keys, and I'm very careful with it, but I still have a few small marks where the black anodised rim has scratched (you do have to look closely to see them).
I guess the point I'm trying to make is I don't think the iPhone 5 will 'age' well. I have my iPhone 4 coming up to 2 years in a few weeks and when I put a new screen protector on the phone, it still looks like the day I got it. I just don't expect that to happen with the iPhone 5.
Not a massive deal, no, but I think they could have done a bit more to make the rim more durable and scratch-resistant - whether it's using a different anodising technique or tempering the metal etc.