Originally Posted by
Grouchi
Here is the heart of the problem. Let me explain.
Blizzard is trying to balance healers to that extent that no healer, or healer setup, is obligational to any particular fight. So all healer setups from, Pala-Sham-Durid / Druid-Sham-Priest / Sham-Priest-Pala etc. is viable to some means on every boss fight. So why bring a Holy Priest when one of their healing potential is crippled by an ackward game mechanic, which in and of it self is replacable(by bringing an equally good Druid, Shaman).
Let me put it in numbers. Every class let's say has the base spells in which increases it's healing output. Should you remove one of it's spells it should obviously lose some of the healing potential it originally had.
Priest - Other spells 90% + Lightwell 10% = 100%
Druid - Other spells 90% + Lifebloom 10% = 100%
etc.
So, why not bring a Druid(or Shaman, Paladin) who can reach this optimal 100% healing output - whilst keeping that ackward-nobody-likes-mechanic where it belongs, in some major afkcity. That is sadly what might happen in Cataclysm OR nobody bothers using a wasted talent.