Glare spam is economical.

Anyone can do the experiment of going to Bozja, chugging the Savior juice and slotting in some Lost healing spells. Then you go from CE to CE, acting as true DPS healer. And while an interesting experience, it can also be one of frustration because sticking to a strict rotation and being available on demand to heal the whole party with 1-2 GCDs of heals do not mix together. That is the key to it, Glare spam can be interrupted with no penalty at any cost, to save whoever just ate some raid mechanic to the face. So an "actual" DPS rotation does not fit into the healing lifestyle.