I wasn't directly involved with the healing change, but TheBluestThumb hits on the major points pretty accurately. Healers cannot heal NPCs at all unless they are in their group or cabal. There are a handful of other healing options as well available, but overall they are all rather poor on the return on investment scale. Mass healing's longer lag and higher mana cost fit more into this category.


Only speaking for myself, I'm fine with a healer having one or two costly options to use.