In reading over the posts on this subject, a couple important points, to me, seem important to know. First, National Socialism started out with support from many people including Joseph Kennedy (father of President Kennedy), Charles Lindbergh, Henry Ford, and others. The social/political system appeared to lend itself to supporting all strata of society while improving the quality of life for a war and depression weary population. So, the fact that many Germans and former royalty initially found the Nazis to be somewhat acceptable (although party membership was definitley NOT inclusive of the majority of people) is no surprise.
Next, the Final Solution was created and put forth in late 1943, well after any early support the Nazis may have garnered from the people or royalty. By that time, many had become totally disillusioned and anti-Nazi. Von Stauffenberg and other nobility who were aware of the crimes of the Nazi leadership did act to end the disaster, but failed, as has most such attempts to overthrow a powerful dictator throughout history.
Remember "Schindler's List"? Schindler was a high ranking Nazi official; clearly he signed up in the early years for what seemed to be a promising future for Germany, but when he realized the direction the party leadership had taken, he did what he could to rescue people. The same is true of many royals as well as regular citizens, realizing the "regular" citizens in 1943-1945 Germany were children, women and old people. All the men from age 15 to 50 were in battle.
Finelly's comments are in line with what I am familiar with, and Israel, for example is sponsoring a symposium on the Hohenzollern family with an eye toward a different, more positive view.