I think americans assume when they see a chinese or asian person working at an american business that they "escaped" china as opposed to just being rich enough to go to school abroad. and has little to no bearing on the amount of intelligent going around.
They've been continuously programmed with insane beliefs about China, which is less shocking when you understand what insane beliefs that they've had programmed into them about their neighbors. The world and your neighborhood are full of evil communists and Nazis who are trying to kill you all the time.
I don't think it's all Americans however there is a portion of them who are not able to grasp the world outside of their borders.
I think it's mainly due to poor education many receive and a very controlled media that suppresses information.
It's shocking considering how much money they spend on education compared to other nations.