Here's an example situation. Let's stay Startup X has one American engineer, but it needs fifteen more of him. For the sake of argument, let's say his skill set is utterly unique in the US. No one knows what he knows but him. So, Startup X needs fourteen more of him, but they don't exist in this country now. There do exist internationals with the skill set, and it would be really cheap to get the internationals to come over, and Startup X would have all the labor it needs within a matter of weeks. Cheap labor, lots of profit. The CEO is seeing dollar signs. But, his partner points out something else. They've got the one American engineer. The government just recently instituted a bunch of economic incentives for students who get tech degrees. Under the same bill, Startup X could also get money to pay the salaries of interns learning a skilled technology trade. Bingo! Their one American engineer could train the new engineers. Each of them might further innovate, have new ideas, form his own startup one day, and they'd be American startups. Yeah, it'll take longer. And, you might not be able to pay them the same as internationals. Since they're American, they're likely to have higher standards for pay. Oh, but right, I forgot. Using international labor is cheaper and faster, our country be damned.
Your example would be a lot more compelling if it took into account a few factors:
1. For a large percentage of those internationals, making it easier to come here will mean that they will come here and stay, which means that all those potential benefits you say will accrue from the use of the hypothetical interns will also accrue from the internationals, only faster. I don't really understand this line in the sand you've drawn between "us" and "them", because what we're talking about is letting "them" become one of "us". Where is the harm in that, exactly?
2. Training interns is hard, hard work, doesn't scale as well as you seem to think, and often isn't feasible at all. Even if it is, it'll take forever, and Startup X very likely won't be around by the time those interns are competent.
Your example would be a lot more compelling if it took into account a few factors:
1. For a large percentage of those internationals, making it easier to come here will mean that they will come here and stay, which means that all those potential benefits you say will accrue from the use of the hypothetical interns will also accrue from the internationals, only faster. I don't really understand this line in the sand you've drawn between "us" and "them", because what we're talking about is letting "them" become one of "us". Where is the harm in that, exactly?
2. Training interns is hard, hard work, doesn't scale as well as you seem to think, and often isn't feasible at all. Even if it is, it'll take forever, and Startup X very likely won't be around by the time those interns are competent.