It depends on the perspective that you look from. I do not consider it racist personally but as something necessary in the current situation otherwise KSA would turn into another USA as it already hosts people from across the world in large numbers aside from all the migrants. Today it is impossible to tell an "native" Afro-Arab apart from a illegal migrant from Sudan, Somalia etc. You just can't.
I do not believe that KSA is a racist society considering all the different families of various origins, Afro-Arabs who make up 10% of the population and all the foreigners who live and work in KSA.
Yet I would like to see some changes but I am not sure if following Spain's example for instance (very easy to get Spanish passport) is the best way.
Spanish nationality law - Wikipedia, the free encyclopedia
Look how easy it is in reality.