I think at this point in the discussion few people don't understand what it is SE did. They just want it fixed. The easy fix is to make cast times longer so that if you happened to get a bit of lag, you would still have a reasonable amount of time to get out of the AoE. Unfortunately, the games entire difficulty revolves around getting out of AoE and so if they did this fix, it would trivialize nearly all the content, especially Titan HM.

I'm not sure what the solution is, but as more and more people hit the brick wall that is Titan HM if you have even a smidge of lag, subscribers are going to drop the game because they can't progress their character. Perhaps if you want to introduce OHKO mechanics the proper way would be more things like the first boss of Temple of Qarn where if you don't get to the properly lit square in time, you're dead.