Growing up as a non-arab muslim in the Middle east, I was able to meet arabs that were fiercely ethnocentric and those that were very against it.
For the purpose of this comment, I will only discuss the negative experiences, although there were many positive ones as well, and I truly consider the middle east as my home, having the fondest memories of it.

There is definitely a culture of ethnocentricity in Saudi Arabia. Nationalism, in the obnoxious and discriminative way, was something I experienced weekly. There was discrimination not just between inter cultures but also between intra cultures, where certain individuals of a specific nationality looked down upon other arabs, and also (of course) non arabs.

What is most hurtful about this issue, is that many people would translate this perceived superiority outside professional and social life, into religion.
I went to an international Islamic school, and I noticed rampant prejudice against non-arab islamic and arabic teachers (who were, often, more qualified than their arab counterparts) by arab students. They did not respect these teachers and refused to accept their teaching, arguing with them constantly.
I also spoke to many recently migrated non-arabs, who shared bitter experiences at being treated differently and their children being treated differently in places of worship. My family had also experienced this many times.

For me, growing up in Saudi Arabia, this issue has always been the large elephant in the room. Again, as I mentioned earlier, for the most part, my experiences in Saudi Arabia were wonderful, and I enjoyed both the culture and the people tremendously, and still today most of my best friends are arab.

I just wanted to shed some light on an issue that I believe needs to be discussed and handled, to allow us to follow the Deen sent down by Allah SWT and taught by His Prophet (SAW) in the best way, and in accordance with the Quraan and Sunnah, and not confused by pre-Islamic cultural practices. Ameen!