For the most part, glass is glass, and while there are differences in hardness depending on the chemical construction and treatment scratches are common.
Sand, dirt, and any debris with a hardness that is above that of the glass will quickly scratch it. Every car I've owned has had a terribly pitted windshield shortly after ownership, especially due to the sand used on the roads in winter.
Moh money, Moh problems.
Current: '16 VW GTI
Previous: '15 M235i, '13 335i, '08 TL-S, '00 Corvette