I tried to sneak in this final question to my comment, but what other option is there for a luxury consumer gadget?
You could argue that phones should just be uglier and thicker and more rugged such that they don't need a case, but I don't think it's very palatable for a $1000 handheld to be taking damage directly for most people when the ruggedness can be outsourced to a $20 case. Nor do I think a luxury consumer gadget can see much success by sacrificing on aesthetics.
Building the case into the phone is exactly what my girlfriend's $120 Android does, and it certainly looks like it cost no more than $120 with its rubber bumpers that already look like they've been used as pencil erasers.
If you're arguing that people shouldn't care so much about the shiny marketing, it's not clear how much people do care nor what the appropriate amount of care should be. A good looking product does help you spend $1000 though.