Rock chips and pitting are usually two different issues. If a rock hits the windshield with enough force, it will chip (star, crack, whatever you want to call it) regardless of how 'hard' the glass is.
Pitting, or your windshield looking like it was sandblasted, probably is a function of glass quality. The windshield on my '85 728i was terribly pitted when I bought it as a 12 year old car, so bad that I couldn't see out it when the sun hit it just right. No rock chips, though. I had a new PPG windshield installed, no problems after 6 years. Still looks new.

So if you have a sandblasted looking windshield, I would vote for poor glass quality. A rock chipped windshield, that's just bad luck.