You give them too much credit. There's like 4 people on the job design team. There's what? 19 jobs now? All the devs play DPS classes so they get all the attention. Healers are just last minute, lazy crap they pull out of their backsides. Making them as homogenized as they are makes it easier to just slap something on all of them so they don't need to spend any time actually designing anything rather than have anything to do with balance. There is no inspiration. If there were, you wouldn't see all these haphazard changes. They have no idea what they're doing or where they're going with healers.