This is basically what happens when capitalism is allowed to run wild. Massive industries consolidate into a few major players who have immense power over their workers. In this case, manufacturers realized that it's more economical to manufacture in China than in the US so that's what they've been doing. Simple economics. They owe nothing to the workers, only the shareholders. The manufacturing centers of the American rustbelt lost, and when you lose in a purely capitalist system, it's pretty shitty. It'll be interesting to see what happens. Trump certainly won't bring back their jobs in any meaningful way. The only way that will happen is if it becomes economical for companies to manufacture here again vs. China. But good luck with that.

I am not anti-capitalism by any means, but I think strong protections against monopolies and protection for workers are probably a good thing for everyone.