In Germany's defense, they never asked for the Euro, it was more or less forced on them as the price for France not pitching a fit about German reunification. Essentially, the rest of the Eurozone is running on Deutschmarks, and calling it the "Euro" instead of the "Deutschmark" is just a face-saving measure. Germany, unlike most other countries in the Eurozone, could announce tomorrow that they were leaving the Euro, and there would be no run on the banks.

There might, though, be a run TO the banks, to deposit your Euros in time to get them magically changed into Deutschmarks.

So, Germany acts like they run the Eurozone, because the Euro runs on Germany's economic status.

Now, why Italy, Greece, etc. continue to remain inside a currency zone that is not appropriately valued for them, is a different question. I would not be surprised that, if the League ever gets control of the Italian government, they will withdraw. But until then, the Mediterranean countries are handicapping their own economic competitiveness voluntarily, it's not as if it's Germany's fault, since it wasn't Germany's idea.