They can do that if they want to lose their citizenship and never be permitted to return or sell their product here.
Does this mean that there would be no importing at all? Or is it rather that people who move away from the US can never sell to this market ever again? How would you even enforce that?
It would mean the latter. And enforcing it would be fairly easy. I have no problem with importing things. I have a problem with AMERICANS making us import AMERICAN products.
If it's an import, it's not an American product.
You can't import something your country made.
Simple solution.
They sell the company, move out of the country, then buy it back again. Or don't bother to start a company in the US in the first place. I know I wouldn't.
Also, you seem to forget a lot of important facts.
1. Not all locations have enough people to do said jobs. Let's say you manufacture CPUs so you need people who are skilled and can work in a clean room. Where do you find enough skilled labor to do those jobs? If you setup a factory in Oklahoma, you need enough people to fill it and just because you have no job, doesn't mean you can or will do THAT job. You seem to think that Americans will just jump at any job within a 100 mile radius. But that's not how it works. An accountant can't become a construction worker just because it's available.
2. Money is not a 1:1 conversion. Cost of living is radically different. Hell, even per state. Even INSIDE a state. NYC cost of living is vastly higher than upstate New York. Which is higher than North Carolina. So pay varies. Taxes vary. The same occurs for other nations. So you can't just say "minimum wage here vs there" because they don't equate. Sometimes it'll be too little, so you're making said country happy to lower their cost. Other times it's the kind of money you make a year, not in an hour.
3. Supply doesn't work so well. Raw materials still need to be imported.