I realize right now healing is difficult for a variety of reasons. Increase enmity, increased mp costs.... Right, I understand its tougher than before.
But maybe this is just giving the new job system a chance to shine a couple patches down the road. For example, when WHM is implemented, what do you think they're going to excel in? Healing. If you ask me throughput is not an issue with our current class system. So what will they improve upon? Perhaps the WHM will be given cheaper heals, draw less enmity from them, recieve a new healing spell arsenal, or a combination thereof.
It would make sense that a job they designed to specialize would be better than its more versatile predecessor.
On the other hand, you have to ask yourself if you think this content was designed for a new job system in mind. Another question would be how well the mage classes can solo after 1.18, if you go by job>party; class>solo I have no idea on either.
Just my thoughts.