Originally posted by Freedon Nadd
Source to back that up?
"The Force moves through the Emperor's Hand in a manner that few others experience. For us, the Force is an intricate tapestry woven into our very essence. That tapestry has become flawed. I speak of a persistent disturbance. A cyst, dense and tangled and unpleasant. It began small and nearly imperceptible but has been growing ever larger... the source of this basal disturbance is of the gravest concern to us..."―The Emperor's Hand (Star Wars: The Old Republic)
Originally posted by Haschwalth
Revan ****ed the with structure(tapestry) of the force, within the Jedi/Sith passively.
Keyword: "persistant disturbance".
From Emperor's Hand it seems that Revan's lightsided presence presented a threat to their dark side connections with the Force. Sort of a passive hinder.