I asked Austin Peckenpaugh (Senior Designer) about Rage and Focus builds and how they're fitting into PvP overall right now, and here was his comment:
Rage and Focus have always been high burst specs, but they haven't been very popular due to some usability and quality of life issues in the past. Our goal for Focus and Rage was to address those issues without significantly affecting their burst. In large part, I think we've done that, but the result is that many people are playing them now, which means there's a lot of AOE burst happening in warzones that wasn't happening before. We're willing to wait and see if their popularity is a result of being viewed as "flavor of the month" (i.e. Rage/Focus populations will naturally subside as people realize the spec doesn't suit their playstyle) or if they are truly too good and were just too unusable before. In short, we're going to keep a close eye on it.
The problem with the Juggernaut and Guardian trees is that one of the trees is seen as no longer any good in pvp due to the amount of burst damage going on and that the tree in question doesn't do enough damage in a short amount of time. I am speaking of course about Vengeance/Vigilance.
If this tree got the buffs it should have gotten then Juggernauts/Guardians would not all be going Rage/Focus, and they would have an alternative that is actually far more useful in pvp (utility wise) than Rage/Focus.