This is all about pleasing the Frogs,they must be seen to be in charge. Also the area keeps ,or used to,changing between France and Germany,at the moment it's in France.
I visited Gerardmer a few years ago, on the West of the Vosges mountains. At the end of the war in Europe, as the Germans retreated, passing through the Vosges, they spitefully devastated large parts of the area. There are few old buildings in Gerardmer, and the Germans are hated for it. On the Eastern side of the Vosges, the Germans continued to retreat, but they didn't wreak such damage. Why not? Because they said 'We'll be back here soon.' So, at least, we were told by people in Gerardmer, whose hatred of Germans (and love of British) were palpable.
Unsurprisingly, lots of towns in that region of France have German names, such as Strasbourg, Kaysersberg, etc. Many of these places are unspoiled mediaeval towns -- unlike those on the West, such as Gerardmer.