I don't know anything about German politics, so my vote is valueless. But perhaps this is still a problem of reunification.

Question: Is migration of German citizens between the old East and West completely free? If so, why don't the unhappy East Germans move west?

Applying my "compare to America without bashing" theory: In the U.S., if you live in, say, Arkansas, and are poor and unhappy, you might move to North Carolina to get a better job. I can see why this is hard if you're moving from Turkey to Ireland, but within Germany, what is the mobility of the population?