Well, the game has horrible latency in showing area of effect attacks and other specials.
Sure, they can be memorized and avoided based on prediction. But I have to ask, how fun is that?
It is one thing to think "oh no, I have to move now or should I finish this cast." vs "I have to move now because in approximately half a second red circle will appear, and If I do not move now I will die"
The latter system currently in place actually makes the game more boring and if any fights are introduced that are truly random, some players will never pass them.
On top of that, if you do not give casuals shinies, they will go to one of the many free to play games out there and spend more in the cash shop on shinies than they ever would on subs to this game.

Games in this day and age need to be very casual accessible to be successful. As a person ages their reflexes deteriorate, and mmo players are increasingly older. They also have the most money, and you do not want to drive them away.