the whole thing is about the documentary The Problem With Apu

long story short, at its core, its about when you have one single minority member in a sea of white faces in a show or movie or whatever and that character becomes the template for said minority in the real world. Its compounded when that one character is made out of stereotypes. Because there is no other character to balance and because most white people only really interact with white people, those stereotypes get brought out into the real world.