I'll take a scripted fight anyday over the complete bullshit luck that is non scripted. I seem to remember very well what non scripted was like when playing a game called Mystic Quest....and the golems(I think) around the volcano along with most bosses. There are times they would do nothing but normal moves and times they would do nothing but try and put stone on you, and it was a party wide debuff not just single. Unless you could kill them in one turn or get the auto attack ones you literally had to bank on nothing but pure rng.

That is not fun when a mob does nothing but spams it's ultimate attack, especially when you have no way of either dodging it or being able to mitigate it every time. The moment you take out that possible ultimate spam and put cds on abilities you have gone back to scripted encounters, there is no inbetween.