Tazria & Metzora: A straight line from tzaraat to Shoah

During our Torah study session at Seudah Shlishit today, one of the other congregants posed a question:  Since the rabbis of Talmudic times claimed that the illness called tzaraat was a punishment for lashon hara/malicious gossip, how would they have explained the Shoah/Holocaust?  So I opened my big mouth and protested that that's exactly why I object to the rabbinic explanation of the reason for tzaraat--if you blame the victim for one thing, what's to keep you from blaming the victim(s) for another?