Roman Catholics would seem not to be deserving of disproportionate blame unless there was some other large Christian (or pagan) group that did not persecute Jews when they could.
Catholics have a long history of persecuting the Jews. Catholics used secular power in areas they controlled or had influence. Also right up to the start of WWII Catholics of influence were engaged in AS.
The claim also has been made that Luther had the 'blueprint' for the Holocaust. Evidence to the contrary depicting Catholic and Nazi similarities has also been presented.
I believe that one's sins are one's own. That the Nazis of any religion are responsible for their conduct. Others here disagree.