I'm sorry, but that's a load of poo. assault has to burn his one dcd for a onetime root/snare dispel. who in their right mind is going to sit on their ONE dcd for one of the handful of moments that they're snared/rooted? most likely, it was necessary just to get to the white bar.
Haha, okay maybe I made it sound better than it is. But having the ability to break movement impairment in key situations can prevent a LOT more damage than the reduction from the dcd.