The Bundesbank's gold is one issue, and the Germans' interest in gold in general is another one.
Some whacky politicians have demanded that the Bundesbank prove that the gold it owns is still in existance in the vaults of central banks in the US, in London, in Paris and elsewhere. Hence the repatriation of the larger part of our Central Bank's gold reserves, just to calm down those politicians.
Germans in general, like people in almost any other country, including yours, buy gold as part of their investment portfolios, if they can afford it. Gold, as you know, does not earn any interest and just sits there; appreciations in value are not guaranteed.
I, myself, have bought the €100 gold coins the Bundesbank has been issuing annually since the introduction of the Euro, but I have ceased to do so since the price has risen considerably, und a member of the European Central Bank has told me that other people here in German have ended their buying of those coins for the same reason.