No, not neccessarily. "Passengers" all have different preferences, but I would say that solid experience and professionalism is what is preferred, over nationality.
In the case of Qatar, there are a large number of Asians and South Americans working on the Amiri fleet, in addition to Europeans, and I don't recall there being too many blondes!!!!!!!. The No. 1 is Thai, if I am not mistaken.
In the UAE, there is more of a mix. There is also one other Royal operation which prefers all male crew, for example.
Therefore, nationality doesn't seem to be the main driving factor.