I think positionals are fun, they give an otherwise bland rotation something extra to pay attention to.

My qualm with them tends to stem from when they're overused or such a significant part of your damage output.

I.e. Monk, where literally every skill is positional and is a massive portion of your potency (40 potency... But for skills like Dragon Kick and Snap Punch that's 40% or 30% more damage from that GCD)

Also, I'm not even a NIN main but I've been triggered so hard by having my Trick Attack fail because the exact second I use the skill the boss instantly turns to throw out a skill and fudges the positional and makes the vulnerability miss >.>