IMO, being unreasonable bad at your job is a reason to kick.

I had a SMN once in Gubal Library HM, no pet out, was spamming miasma, Bio and Bio II, and by spamming I mean he out them up, and them out them up immediately again. never used aetherflow which meant no Fester or Bane.

He was unreasonably bad at his job to the point where he could have possibly been trolling. Our party agreed to kick him.
I consider kicking BLMs as well that don't even attempt a rotation and rather used things like Flare at full MP in Umbral Ice stance, sitting there in fire until their MP naturally ticks up for a Blizzard III.

There is zero reason anyone should have to tolerate that.