Reaction-based mechanics are usually friendlier to casuals since they tend to involve less instant death and/or allow more time to recover from mistakes. It's the common trade-off for the possibility that the RNG might be unusually cruel.

And Dererk, grats on your clear, but even that situation is an example of responding to scripted mechanics. What you did was choose the most appropriate response; the only difference being that you were forced to use certain cooldowns because your party members failed to handle their scripted elements and got killed :P