Do you have to be Asian (ie. speak Chinese) to work at a bubble tea joint?

I have never seen someone who is not Asian working at a bubble tea store. I live in a big city and have been to 15+ stores. Obviously they don't discriminate on race (that would be illegal), but I'm assuming speaking Chinese is necessary, and most people who do are Asian. So is it mandatory or is it simply a coincidence (as bubble tea originated in Asia)?