I believe it's a deep feeling of "wait, we can't just perpetually be giving each other haircuts". Consider the collective value of all the physical goods impor

I believe it's a deep feeling of "wait, we can't just perpetually be giving each other haircuts". Consider the collective value of all the physical goods imported into the US. Without any production in the US, that sum would have to be compensated by non-material exports only, or it will, sooner or later, result in an economic imbalance. While there are certainly some high-value services and intellectual properties that can be sold across borders, it makes people queasy that so much of the country's productivity is tied up in law, finance and other zero-sum arenas that are essentially masturbatory. It seems unsustainable.