Cui bono.

(…) says Jeromin Zettelmeyer, a former economic official in the German government and now a fellow at the Peterson Institute for International Economics in Washington.

Germany does have an advantage, he says, but „the only sense in which I think Germany could be accused of ‚cheating’ is by being a member of the [eurozone]. There is no question that if Germany were to exit the [eurozone] today, this would lead to a pretty substantial appreciation of the German currency.”
(…) if Germany still had the deutsche mark, its products would almost certainly be more expensive and less competitive in global markets. That’s because the deutsche mark would reflect the real strength of the German economy. The euro doesn’t.