That's so not true! Traveled to Dubai with both an American passport and a Pakistani one. You are Definately treated better with an American passport even if you are of Pakistani origin. This time traveled with some relatives from Pakistan especially young males and those with Paksitani passports got lengthy investigations while the American passport had no line, my sister even over stayed her Dubai visa and there was no trouble or penalty. I've heard people with Indian or Pakistani passports who over stay are given lots of trouble.
I am not saying its better but Arabs are suckers for anythign western.
I can confirm that. I had never been to Dubai when I had a Pakistani passport.
Now that I live here and travel quite a bit, I have gone through Dubai immigration quite a few times. And on some occasions, immigration officers have shown some weird attitude before seeing my passport. And when they do see it, they suddenly become much friendlier. I hate these kind of suckers.