Cathar Castles?

There is an interesting difference between the Tourist Board emphasis of the castles of the region being Cathar Castles, and the leaflets and books at the castle gates saying that the castles merely sheltered some heretics for a few years. The emphasis here being these were castles loyal to the French king and any nasty heretics were quickly dealt with by the hero, Simon de Montfort. 
No mention is made of the wholesale massacres and burnings. The church point of view reigns supreme. Info-leaflets issued at the gate give no details of what happened. One must be willing to spend half an hour delving into the weighty tomes in the bookshop to discover the beliefs and fate of the Cathars.