It was (is?) a real low on the books. It was a politcal statement and was never meant to e enforceable or actually mandatory with many exemptions.Snopes
has a quick read about this. It also goes on to explain that the crime rate pretty much coincided with that of the rest of Georgia.
I believe if baddies knew more good guys and gals had guns to defend themselves, and were maybe slightly less at-legal-risk to use them to defend themself (and their property) than crime rates really would go down with a cause-effect relationship.