I don't think it's necessary per se, but Cleric Stance adds a sense of risk to DPSing. I think most people have misjudged a situation where they activated CS a split second before half the tank's HP suddenly disappeared.

That said, if getting rid of it would encourage more healers to actually use all of their spells, I'd say it's worth the tradeoff, even if I personally find stancedancing enjoyable.