What we learned from the Nuremburg trials was that you can just do things. On one hand in the sense that the Nuremburg trials had no real legal basis and were basically made up ad hoc, it wasn't illegal to do what the nazis did prior, as indeed most of the winners of ww2 had committed and would go on to recommit similar acts. But on the other it also shows us that you can just do things once attention is no longer on the matter. As soon as the eyes of the USSR and the US were elsewhere the surviving nazis were let out by West Germany and the whole thing was made a farce.

There are people who committed acts of petty crime who served longer sentences than mass murderers tried at Nuremburg, and the "Just following orders" defense worked for many.