Two reasons:
We don't make ANYTHING here anymore!
Too many folks on the dole!
Wondering: Silicon Valley, GM, Ford, Dodge, Boeing, Caterpillar, John Deere, Commodities (as in foods), Timber, Oil and Gas, Coal, Peterbilt, Cummins, Locomotives, Rail Cars, Steel, Gas Turbines, etc., etc., are these all just apparitions?