Back then in Binding Coil Turn 5 against Twintania, I used to spec into 30 attribute points into Vit with Vit/Acc/Crit melded i70 accessories on my SCH when undergeared (i70 Vanya gear) to survive Fireball/Conflag/etc. Same thing for i90 accessories in Savage Second Coil and Final Coil.

Vit is useful if it will help you survive a mechanic you would otherwise not without it. As a SCH, you are generally expected to dps more in raid content so sacrificing too much Mind stat for Vit may not be worth it. Not to mention, having more Mind increases your shields, which may save a party member that is weakened, etc.