As most people are aware CC wasn't needed all that much in WotLK but in every other era of the game it has been powerful and needed. Everyone should learn to use it. It is definitely a skill to CC a mob properly, let alone two or more. When doing the same old dps rotations for the millionth time gets boring it can actually be quite fun to try CC as many mobs as you can with Seduce/Enslave, Fear, Banish etc. If you can Enslave a mob you could actually "CC" 4+ mobs at the same time by using the enslaved mob as a tank while you and Fear and Banish at the same time. This doesn't really allow you to do any significant amount of dps directly (enslaved mobs can do a lot of dps though) because it's pretty hectic to keep on eye on many CC's but it can be a lot of fun.