This is not entirely accurate. We have primary source documents about Catharism and you might want to look at Emmanuel Le Roy Lauderie “Montaillou: The Promised Land of Error” and John H. Arnold “Inquisition and Power: Catharism and the Confessing Subject in Medieval Languedoc.” Both are secular historians and Arnold’s book has a very good introduction to why Cathar sources are so tricky to nail down.
In any event, as a previous poster has stated, I’m not sure what your getting at. The southern French crusades are hardly “disturbing” given the social and cultural context of the medieval period. To be a heretic was not a private issue or a personal choice, it meant being a traitor and a contaigon. Further, Catholicism had tried preaching against the Cathars (one wonders, if what they taught is unknown or benign, why would the pope bother to send missionaries into southern France?) until they killed his legate (Peter of Castelnau I think) which enraged the pope and thus…crusade. One also has to add in the desire or nothern French families to augment their wealth by appropriating lands taken from Cathars or their aristocratic supporters.
In any event, lots of scholarly ink has been spilled on the Cathars.