I think that everything comes from China because it's cheaper to produce it over there. Fewer labor costs, and less environmental controls.
We have been trained to shop by price first and foremost, for years, and this is one of the consequences.
From what I've been told by folks in the textile industry, all the cotton combing and weaving equipment left our shores over a decade ago. Even if we *wanted* to bring it back... that would take quite some time. And we are an impatient society.