In the build-up to World War II, the French military created the Maginot Line. This barrier, which utilised state of the art military defenses, was intended to defend France from a ferocious assault by Hitler's armies. When the attack ultimately came, the Germans made quick work of the Maginot Line by going around it through Belgium.
The European Central Bank's (ECB) obsession with a 2% inflation target can be seen as similar to the construction of the Maginot Line. The ECB sees achieving this inflation target as the sum total of the central bank's responsibilities for maintaining stable growth in Europe, just as the French generals viewed the construction of the Maginot line as defending France from a German invasion.
The main difference is that after that German conquest, the French generals recognised their mistake. By contrast, even after their 2.0% inflation obsession led to economic disaster, the people running the ECB are still in charge and still pursuing the same policy.