Assuming a DRK is facing 3 or more targets, their DPS starts to go up a lot, and Bloodbath goes from a guaranteed healing potency floor of 256 potency per use to 360 potency per use (assuming you have Blood Price available and don't use something that increases your Evasion chance). 4 targets goes to 480 potency, and it only gets higher as you have more enemies you can hit--and all this in addition to your autoattack.