The actual problem - since he seems incapable of pointing it out - is that it can basically instantly heal any party to full health out of combat with almost no investment at all. Out of combat healing isn't the problem, it's the amount; it's almost 4 times as effective as Prayer of Healing, making Life Clerics basically redundant out of combat now (Not that anyone was using PoH anyway, which is a problem in and of itself).

They've given the best out of combat healing in the game to the ranger and not the most traditional healing class in D&D. There are also DMs who don't want their players to just top back up to full health in less than 5 minutes after every fight, but that' a per-table scenario.