In theory BB could nullify the ice isn't not??
He could save his crew that got frozen........Gura Gura was a petty excuses to show us the reason he can't, everybody knows he had other fruit that is better to deal with it , Loda strikes again, literally you can't use logic in this story.
He introduces a power that has specific roles and certain uses but yet when it is required he acted like that power is non-existent.
That's why haki is also inconsistent as hell.