I've always put a case on my phones so, while design and build quality; as subjective as the last item may be, are important, they take a back-seat to the usability of the device according to my needs.
Your device needs are likely different than mine so it's sad that we can, and usually do, get into endless and, frankly asinine, debates about elusive criteria that make up "build quality". At the end of the day, these devices serve a purpose; they are communication and media consumption tools. Sadly, for some they are also a means to self validation - filling a void in their life.
Don't get me wrong, I like quality made goods and I have a very active nerd gene; that's why I visit sites like these. I am, however, thankful that my self esteem isn't indexed to a device that buzzes in my pocket!