On my witch hunter numerous times I scroll through the combat log to see what has killed me and its (not a joke) about 60% riposte.
I honestly struggle to see how 1 tactic can provide so much entirely passive damage that it compltely carries fights.
Its even worse on a WH with low armor because the riposte just shreds your low armor.
Virtually every proc I see has a timer. Yet this effect which seems to have more damage than many other procs basically doesn't.