Only because she was pretty much given over to the Dark Side, Mace didn't want to kill her, and he was exhausted from having dealt with a mountain of shit in the events of Shatterpoint. The limited darkness she encountered on that planet broke her, to the extent that when Order 66 took place, she was pretty much in a waking coma. Vitiate, mind dominating or no, is a foe well beyond her powers, and that of Bulq. Mace has a chance if his two friends can buy him time with an incredibly well-oiled ploy, but as we've seen in the past, power duels almost always favor the single combatant. Only when it comes down to 1v1 that things come close to level.
Look at Maul TPM, Sidious ROTS, Dooku in both AOTC/ROTS, and so on. Force users usually end up being more of a hinderence to each other than a help. Now, Bulq, Depa and Mace have some value as a team (or at least, Depa and Mace do; they have demonstrated teamwork in the past). The problem is that they must maneuver themselves past the ridiculous Force powers Vitiate can rain down on them while trying to close the gap and kill a guy who can defend against a flamethrower using just his powers.
The same guy who killed an entire Dark Council solo. You know, that guy.
Yes, Windu was holding back. However, he does claim that she is a superior duelist. Perhaps one could attribute that to Windu's humility; yet, when one considers both Windu's statement and Depa's performance, I think it fair to say that at the very least she rivals him.
As for Vitiate, he is not undefeatable even at full power. Revan held his own for a bit and the Exile could have killed him. Taking down the dark council is all well and good, but the feat is frankly far too nebulous to be anything more than a curiosity. Not only do we not know how he did it, but we do not know how powerful those council members are.
Windu often though gives above and beyond credit to duelists, including his own apprentice and Obi-Wan Kenobi. He's surprisingly modest for one of the foremost duelists of his era.
Also, you forget - Revan had mastered both sides of the Force to a degree pretty much unheard of, and for that reason alone he was -almost- able to give Vitiate fits. Revan's exotic mastery of the Force eclipses Mace's more practical and mundane usages of it, and Depa/Bulq have no Force feats on the table to really speak of, so there's that.
Also, I'd rank Revan, Meetra, and Scourge a lot higher than Mace/Bulq/Depa in terms of capabilities and effectiveness against the Sith Emperor. You can dismiss the feat of killing the Dark Council all you'd like, but the idea is that fighting multiple opponents is not an alien concept to Vitiate. In one of the TOR storylines, he pretty much obliterates a few Jedi Knights/Masters with his lightning alone, and his variety and proficiency with the attacks he uses in just his fight in Revan is far beyond that shown by ROTS Sidious or any of his competitors in this thread.
So again, it boils down to them working out a battle plan, in which most will die, to get Mace in the right place to strike. Otherwise, he ragdolls them.
Stealth Moose
Windu often though gives above and beyond credit to duelists, including his own apprentice and Obi-Wan Kenobi. He's surprisingly modest for one of the foremost duelists of his era.
Oh yea, he likes to talk up everyone. Great skills, but I don't think he's the most objective in judging others.
Originally posted by Lord Stark
The team owns him. Revan and the Exile could have killed Vitiate if the Exile weren't such a shit Jedi and put attachments over the fate of the galaxy.
That doesn't really apply, since Vitiate wasn't aware of the Exile until she attacked. Its like saying that Sidious is shit since Vader was able to grab him and throw him off a ledge. Those kind of sneak attacks aren't relevant in a face to face combat situation.