They believe that Malion's assassination had made martyrs of the Portori.

The Cabalists were largely neutral during the Rebellion. When Malion called upon them for aid, they adopted an isolationist policy, disquieted as they were by his many excesses. They did not seek the fall of the Protectorate--believing then, as they do now, that only a united Vale is capable of surviving in the long term--but thought they would be in the best position to take power after Malion and the Rebels took care of each other.

They did not expect the Rebels to outright win--but they do see the advantage of free minds and free choices.