Originally posted by Lord Stark
Really because Sidious doubts he could take him fairly methinks.
Sidious at that point has no telepathic feats to speak of. Plus wasn't Sidious able to defend against Plaguies' mental probings while barely trained, if at all? Vitiate on the other hand is superior to the Dread Masters who can enslave armies with the TP, has torn apart the minds of dozens of Jedi who got close to him and Plagueis lacks the knowledge of how to defend against his mind.