I understand that clerics are powerful, but look at the tactics a cleric would use if not for a band of blood thursty melees going to get killed or at least find out how much damage they can take before the mob dies. Clerics wouldn't melee something, they are similiar to casters and use stretgic placement of their spells.
6 clerics in a group will always be powerful since all they have to do is worry about themselves for healing, not 5 others and themselves. what makes a cleric less powerful is the other classes around them, as you say, we are played out to be healbots. And yes I have a cleric too.
Again, apologize to hijack, but the overall point is as classes are "balanced", clerics need to be adjusted to relate to the changes of the evolving class.