Why are syrians and turks more diverse looking than saudis and kurds ?

Turks are not even so diverse looking like some people claim I can often detect turks but they are still more diverse looking than kurds. There are blond turks but Ive never seen a blond kurd in my life. And Syrians didnt have a empire like the ottomans so why are they on average more blue eyed/white than saudis ?