BASF's largest plant in Germany was hooked up directly to Russian gas. Russian gas is now going to China. So are BASF.
I don't think regulation or subsidies are to blame either. Eastern Europe is receiving heavy investment because they have costs for workers under control and can provide a more stable political environment. The problem with Germany specifically is that they papered over a lot of bad fundamentals in the early 2000s with cheap energy and very close relations with Russia.