What business is it of mine if immigrants to the USA look like middle-class Germans or poor farmers from Chiapas? Did God put me in charge of judging what is good and bad for “the U.S. economy” or for the USA as a whole? Did he put you in charge?
Casting government immigration policy on the premise that the former sort of immigrant should be given preference over the latter is, among other things, bad economics. Those who think differently need to master the concept of comparative advantage. Gains from trade are ubiquitous so long as the market is open and all transactions are voluntary.