I hire a programmer to code my app, SuperConnect++. I charge $0.99 to download the app. People buy the app if it's worth more than $0.99 to them.
If 150,000 people buy the app, then I have ~$150,000 of revenue. I can pay a programmer $100,000 a year and have $50,000 left over. 150,000 people benefited from the app.
Now say I have to pay an additional $100,000 visa fee for my programmer. My cost of $200,000 is less than my revenue of $150,000. I don't build the app. I don't get $50,000. 150,000 people who would have bought the app don't benefit from it. The biggest loss is to the Americans who don't get to buy the app.
There are other possibilities, maybe I increase the price to $1.99 or I hire an American. We can see that those are both bad. The former extracts $150,000 extra dollars from American consumers. Since unemployment is low for Americans and an American programmer can't have two jobs at once, the later just means that some other project that the American programmer would have worked on is not completed.