Buyers/ 'The Market' demand good quality, low priced goods. Producers & companies want to make maximum profit. They go where there is a large pool of trainable workers who work for much less than you or I.
It does not mean these people produce cheap crap, it is often very good quality & the technology comes from the West.
With the possibility of getting banned if this is considered "political" I have to say that I disagree. What Buyers/'The Market' demand is the lowest price--and to stay in business, that's what companies provide. For the average consumer, quality hardly ever enters into the equation. Which is why the WalMart, Harbor Freight, and other companies do a bang-up business in cheap, shoddy goods. Generally, "these people" (whatever that means) do produce cheap crap--and for some disposable items, buying cheap crap probably makes sense. But that doesn't mean it makes sense to source close-tolerance parts used in critical components like your engine or brakes from some third-world country where the definition of quality control is that the part got sold before the defect was found.
Unfortunately, Americans seem to have traded the traditional idea of "you get what you pay for" for a kind of short-term thinking that's led us to the brink of a complete collapse of manufacturing. Most citizens don't seem to understand that you can't have a society that sells and consumes and doesn't produce. It's not sustainable.
For myself, I try to only purchase US-made items when I'm looking for something that's intended to last more than a year. I may buy the occasional foreign-made disposable (a toy that my four-year-old is unlikely to keep, for example) but I usually avoid them. This means that occasionally I have to buy a used tool, or borrow one, or make something myself. Sometimes it means forgoing something that I'd like to have... because we've reached a point where there are some things where a US-made version cannot be had at any price. But personally I've decided that I'll do without some things to avoid contributing to the problem.
To bring this somewhat back on topic: Good luck to the original poster. Let us know what you find and how hard it is to meet your goal of all- or mostly-US sourced parts. I know that at some point a lot of us will be in the same situation, and it would be good information to have if you're willing to take the time to share your experience.