Nynaeve was appalled by the massacre and the dangerous weapon employed. How a person or persons is killed makes a difference. a regular bombing compared to Hiroshima. Both horrible but one more terrible because of the destruction to the victims and the danger to surviors as well as the actual assailant.

We know for a fact that the DO can recover a balefired thread within a certain time period. the severity of the balefire doesn't change the type of damage done to the thread. So if the thread is still usable to the DO then it is still usable by the Pattern. Any interpretations to the contrary are an error on Sandersons part or on the readers part. You can chose which you want but those are pretty much the only options. RJ has established how balefire works already the thread is removed. Not destroyed.