Why not? Because what evil puppet-master settles for "probably ok" when a slight extra effort buys certainty.

One that isn't totally neurotic, presumably. Just to reiterate, I don't believe such an organization exists. But when trying to understand the plausible actions of even fictional characters or organizations, I try to imagine myself in their shoes. If I were in their fictional shoes, I would ignore the people who say I rule the world if those people are widely mocked and derided as insane by the general public. To do anything other than ignore them would be to risk giving them a sliver of credibility.