I constantly see the argument that content isn't designed with healer DPS in mind. However assisting your group to the best of your abilities (this goes for all classes) does smooth out a dungeon/raid/etc. No one's in a rush to get to the end, but actively assisting your group with always casting something beneficial (heals if required, DPS if people don't need healing) seems the best way to do it.
This is in the same camp as NIN's using their Shadewalker, melee DPS in general using Goad on the correct person, bards using their songs correctly. Do what's best for your group.