For me: When a phone 'requires' a case to protect it from gentle use, even of putting it on the table so it will not get scratches is absurd. My iPhone 5 got scratched up before my case arrived, and I was so careful with it. I attribute this to 'build quality' also, it's not just how it feels.

I think Nokia phones are more "sturdy", exemplified by its cheap phones that just won't break. Apple is more meticulous I'd say. I have a Lumia 920. There are just tiny little seams and creaks that one wouldn't find on an iPhone.