This is obviously most useful in BGs and arena. The biggest problem with killing the grounding totem in arena is targeting it, and then casting something to kill it.
Right now Righteous Defense is bugged so that if you cast it within 40 yards of the totem, it will be grounded by the totem, thus killing the totem. This is MUCH easier than manually targetting/casting on it. It doesn't always work, but has been about 75% of the time in my experience.