I wish that you'd actually type proper English.

The point was, even WITH Amaterasu, there's still plenty of reason to run her. Even in content which has no debuffs on you, she still has the highly valuable combo- debuff. She's only useless in content which does neither debuffs on you nor does ever do normal attacks.

But no, everyone just looks at her -15% B debuff and goes "USELESS POINTLESS TRASH."