Doesn't mean it should remain in the current form. Costs one batch of AP but can trigger direct heal procs 10 times. The only other outlier like this is Inevitable Doom which costs AP once and then keeps triggering direct damage procs.
If Ritual of Lunacy is to keep being able to proc stuff on each pulse then each pulse should cost AP. And I say this as one of the most zealot-biased people on the server.