Yeah it's an odd decision, putting the cap for accuracy so high, and then making it difficult to reach that cap unless you get really lucky on drops, or sacrifice vital stats.
Kinda really important for Tanks to reach cap for these things, since we often have one hit to really pull enemies, and missing can potentially derail the whole raid.
Edit: For context, it sounds like I'm at or near the Accuracy cap for the first few turns of second Coil already, but that'll change the moment I switch away from the Dual Haken. Not even the High Allagan Axe has as good an accuracy stat as that axe. So I'm immediately going to have to find a way to make up near 30 ACC, even if I don't swap out any other ilvl90 pieces with ACC for equipment with none. : /