Beats the **** outta me. Maybe some things needed to be in place for it to work right?
As I understand it only has so much reach, or area of effect, and if he'd have done it in the outer rim the only ones affected out there would have been those planets. I think his plan was to get as many lives as concentrated into the galaxy as possible before doing his ritual so that it could absorb the most amount of lives. At least that's the way I understand it.
Sort of the same problem as Nihilus I'd presume. It's localized (relatively speaking).
Still, an anonymous Jedi Knight can kick Vitiate's ass, so...yeah. Considering the note at which it left off, I don't think we've heard the last from him...nor a few other characters.
To keep it relevant: I do think we could see some variant of "splinter of the mind's eye" action in the next confrontation regarding Vitiate and at least a couple of other characters, which probably won't happen for some time. Just a prediction. I'll leave it unsaid as to whom and what, but if you know what I am talking about referring to that story, then you'll know where I'm going with this.
Would this by any chance have something to do with the development of your mod?