These days, China has substantial value as a consumer. It makes sense to keep some (but not all) of your manufacturing where you have a billion consumers.
Seriously, that has been proven false decade after decade after decade for over a century now. Perhaps two centuries. Look at jet engines. Western manufacturers were enticed to "share" technology and manufacturing techniques to get a part of the Chinese market. And now:
"China's cabinet may soon approve an aircraft engine development program that will require investment of at least 100 billion yuan ($16 billion), state-run Xinhua news agency quoted unidentified industry sources as saying. China is determined to reduce its dependency on foreign companies like Boeing Co (BA.N), EADS-owned Airbus EAD.PA, General Electric Co (GE.N) and Rolls Royce Plc (RR.L) for the country's soaring demand for planes and engines."