The whole idea that it would be wrong or humiliating to have to train someone who had the gall to be born in a different (and generally poorer) country is based on the notion that Americans should be treated with more regard than people born elsewhere. If Disney had fired 200 Americans and replaced them with 200 other Americans, would there have been an uproar? Almost certainly not. Since they only difference is the new workers' nation of origin, how is this not a xenophobic or racist reaction?
Lots of issues are complex but complexity is not an excuse for xenophobia.