Before 6 I always used a screen protector and leather slip cases.
With the 6 & 6+ I don't bother.
Both new iPhones are kept in flip wallet type cases (Pad&Quill) and no scratches whatsoever.
I miss holding the device in my hand with no case/wallet though.
I too wonder if there are some QC issues.
That said, an iPhone cannot scratch unless something is scraped across it's surface - take responsibility for your possessions people!
If I scratched my iPhone by putting it in a...