The key word is BUSINESS! China or Indonesia it's all about money! if one has not come to the point where one understands this how can one be a good teacher? some schools focus more on the marketing and money so they only need a good looking face, others put education next to money they require skilled teachers, they all prefer white as the customers want this.
Some schools have had so much bad luck and do not understand how to pick a westerner they just give up and take a non westerner. they may lose money from this but its easier for them they trying to figure out why its not working. The smart business will pay top money for a westerner who has skills and they will make more with that as well.
Look around you most business models that make big money come from the west, in Asia we slow down to enjoy life more, the west works for money and more money, this can be seen right here with the Indonesian and Chinese, one works for money the other works to eat, right/wrong, no just a way of life.