against a priest/rogue, my rogue will 9 times out of ten get the jump on there rogue because of our well executed opener, and I can spam spellsteal on the rogue the moment he gets pain supression and it may not even take it before its fully ran out of time, making me completely waste 4 or 5 global cooldowns worth of time, and time is of the essence for cc and the rogues bursting eachother. Just 2 examples, theres more examples, but the point is you cant be skillful and use timing with something that has such a sloppy mechanic.