It might be a useless, militant union but it is the only union cabin crew belong to ....
Not strictly true. There is Amicus, but both it and BASSA have come under the umbrella of the TGWU. Amicus members are not at all happy at being dragged under by the buffoons at BASSA., and neither are other BA work groups in the TGWU fold.
.... sadly I feel regardless of how self inflicted the latest situation has arisen most crew will be backing their union causing untold damage to BA and eventually themselves.
Damage to BA? I don't think it will be anything that BA hasn't planned for, and therefore any possible damage will be contained and limited.
Cabin crew doing damage to themselves? Well if they are aware "of how self inflicted the latest situation" is, but are still going to stumble lemming-like after their union clowns, then they have
only themselves to blame.