Trummerliteratur was a literary movement in Germany that grew out of the rubble of World War II. In fact, trummerliteratur means "literature of the rubble".

The new literary movement emphasized fractured sentences and minimalist style. Trummerliteratur signified Germany's entrance into the "modern" literary environment.

Prior to the war German literature was made up of nationalistic tales and Bavarian mythology. But German shame after the war forced a change in culture.

I guess it was decided that art like Wagner's wouldn't send the right message to the rest of the world.

Source:
"Speak Not, Memory" by Ruth Franklin
The New Republic. August 20, 2001, p. 30-39