I mean come on nothing is going to be scratch resistant, and if people for example but it in a pocket with keys of course its going to scratch. Almost suicide for a iPhone putting it in a pocket with keys!
Actually it won't, the metal in keys is softer than glass, try it on your old iPhone, you'll be surprised you can take a key to the screen and it wont scratch. You would either need an unreasonable amount of pressure, or a material harder than glass to scratch it. (Diamond, Quartz).