None of these two served any prison sentences. Wulff was acquitted after he refused to pay 20k € to make it instantly go away and even had damages paid.

Guttenberg was caught plagiarizing for his doctoral dissertation, which is a rather common thing among German politicans. As a consequence he lost some public clout, but instead wrote a book for even more publicity, afaik right now he's doing some work for Springer in the US, biding his time for a another comeback in German politics.

Meanwhile to this day even Kohl's donation scandal, hasn't seen any proper investigation, nor the Amigo-scandal, NSU-scandal, nor the countless others, particularly on a local state level.

Heck, just look at people like Mehdorn and projects like the BER construction site: He, being such a highly renowned and well paid manager, was supposed to fix that mess. Nothing was fixed, the whole thing is still a massive mess, political consequences for anybody actually responsible? Pretty much zero.

The thing is: We Germans are very good about keeping up appearances, as a result of that inconvenient truths and topics often fall by the wayside.