I mained an emp def all thru retail. Even back then, I was only putting it on toons that needed it (blasters, trollers, etc), and only if we didn't have a bubble mez (sonic, FF). Empathy whackamole is already kinda tedious, I'd rather spend my time attacking thru my current target than buffing down the line a million times.
That said, I wouldn't mind making CM a TAOE with a higher end cost + longer recharge. Taking the tedium out of Emp is tempting 🙂