I think it's a clever ad, actually. Because let's be honest, to advertise a Jewish Museum in Germany as if it's only about the Holocaust would be insulting to the Germans who are alive today. Why should it dedicate more attention to that part of history than any other Jewish museum in the world just because it happens to be in Germany? Now, if it's a Holocaust Museum, that's different, I expect lots of WWII history there. But if I go to a Jewish Museum, I expect to learn things about Jewish history and culture in general, not just about a 5-year window, no matter how destructive it was.
Think of it this way: would an American Museum in the Middle East make any sense at all if it focused mostly on 9/11?