Could be. I just feel like it's the sense of being the cause. I mean as in the Guardians being the cause of the extinction of the Cabal. Though, seeing as though we helped Calus on the Leviathan, he probably signed over the rest of the Cabal to be under the service of the Vangard. They have no leader, no empire. All they can do is look to the second most powerful race in the system and fight with them.