The truth is that Wagner’s popularity was already in relative decline during the Weimar Republic and simply fell further, more quickly, under the Nazis. During the last years of the Kaiser’s Germany (and despite the cost and privation of the First World War), the Master’s works were still hugely popular, accounting for over eighteen per cent of all opera performances, a share no other composer came to matching. By the mid-1920s, though, the figure had dropped to around fourteen per cent.
After Hitler took power, Wagner’s share plunged to well below ten percent.
The truth is that many Nazis, in high and low places, were bored to tears by Wagner.
That is all from Jonathan Carr’s excellent book The Wagner Clan.