That's natural, upper class makes money from assets, not from work - it's hard and also probably morally impossible to tax these (do it and they sell and buy assets abroad where assets aren't taxed, and just throw country into shit, leaving generations without pensions and without profits from their consumption). Only something that has no way to run away, can be taxed. Labor is that thing: for all the bad things about America, you have to build walls to keep people out not keep them in.