As much as I tend to disagree with Proth, he's correct here. BLU isn't a job with high attack and thus will almost never be in a situation with capped ratio. Capping accuracy is child's play now. STR is always useful as you need + ~60 STR to cap fSTR on a 90 Almace, that's not going to happen on anything worthwhile outside of Abyssea.

The main source of a CDC BLU's damage is that WS not their spells. You will use your spells to self SC with CDC for additional damage or for setting useful buffs / job traits. You can also use yoru spells to finish something off without having to waste TP on a WS when it's almost dead.