I'm drawing from my time playing the old FF titles on SNES, and PS1, and in those, confussion effects are the WORST.
An enemy hits me with one and whomever is effected spends the duration of the encounter beating up on everyone but the enemy, sometimes dealing enough damage to one-shot someone. Yes, I know I can hit that player to break it, but I just hate to waste the turn. Either way, SOMEONE on my team is getting hit by me, and when it's an AOE confussion... God, I just want to break the controller as I watch my team spin around like 'tards.
What's most annoying/insulting, however, is if you use attempt to use it on an AI enemy. 50% of the time it does nothing. 49% of the time, even though it's supposed to make the victim attack a random target, they hit one of my guys anyway. I left a 1% margin of error, because I like to believe that some place, at some forgotten time, in all my years of gaming, an enemy did once attack itself or its allies. I need to believe.