Corruption is one of the big reasons. China does not recognize patent protection and many companies have lost everything when Chinese managers basically stole all the product designs and equipment and started to produce knock-offs.
The government even gave a veiled threat to Apple, of all companies, to not investigate working conditions at Foxcom ( I know I mispelt the name). I think that woke up many companies about the realities of manufacturing in China.
Fact is, it is (long) past time to bring manufacturing back to the USA.
Turn it around. Big time.