Ok, I'm going to reiterate this quote chain to show how it makes no sense.
1. Someone says Greyhawk is a generic fantasy setting, so it should have all the PHB races.
2. I say if you make Greyhawk have the same slate of fantasy races as FR, you're making it more generic.
3. You say Greyhawk and FR are so similar that it makes Greyhawk generic, so it must have the PHB races.
4. I say that's why it could be better for Greyhawk to have different race selection, so it's less generic.
5. You just reiterate 3 with a metaphor.
Like, what do you want? FR with a different name? Because I want a different setting, one that feels different. Seeing the same races running around makes me feel like I should just play FR with a different tone.