The thing is Greyhawk isn't "low magic". It's low magic frequency. However adventuring parties is where half of the spellcaster are. Every spellcaster is a hermit, a wanderer, an apprentice of a hermit or a wanderer, or an adventurer. It's not that there aren't spellcasters. It's that 80% of the spellcasters in a given area are travelling together.
You don't meet spellcasters because the spellcasters you'd meet are in the party already. All the magic items anyone sees are in the hands of some adventuring party and the broken remnants of one.
Greyhawk is very personal and that goes with the magic. It makes sense that half your party are spellcasters. That's the whole reason your are together. Because you are greedy or ambitious and want the tough companions you can get of your alignment.
You don't meet spellcasters because the spellcasters you'd meet are in the party already. All the magic items anyone sees are in the hands of some adventuring party and the broken remnants of one.
Greyhawk is very personal and that goes with the magic. It makes sense that half your party are spellcasters. That's the whole reason your are together. Because you are greedy or ambitious and want the tough companions you can get of your alignment.