The Illuminati aren't trying to takeover the world. They've been given a bad rap for 100s of years. The Illuminati wanted Austrian acquisition of Bavaria. Bavarian loyalists defected and gave exaggerated testimony to demonize the order. House searches and confiscated documents seemed to support these claims, plus the continued existence of the Illuminati in Northern Germany was seen as evidence that they were still up to no good (despite it essentially being a masonic reform movement at this point). Robison and Barruel spun all of this into conspiratorial narratives about the french revolution, which later authors have interpreted depending on their own views.Nuke them.
And then the Illuminati can finish the job.