here is the point
if ur group dont have pally, u got no freedom, u will get root, blind, sheep, forstnova, etc,
yes priest can dispell, but what if he is been attack by other team?
i dont think he has time to dispell you!
most of the time there are 2 healers for a 5v5 team, one of them will get counterspelled or feared, and other will be under heavy attack by other team's dps, they dont have time to look after someone who's getting CC.