The true reason has to do with use of capital. The US has perfected a system where capital is highly rewarded for pure financial operations: stock market, futures speculation, banking, real state lending.
Manufacturing requires a lot of capital that US players don't want to tie to a lower reward structure. Germany and Chinese capitalists are completely Ok with employing their capital for manufacturing for political/structural reasons.
That's why American economists will make thousands of excuses that really make no sense when it comes to the fact that they want to invest as little as possible in manufacturing.