And even if it did, that kind of move invites some major retaliation and the Librarians would know that.
That doesn't seem to stop anyone these days.. Wars are fought differently now, they are very sneaky, impossible to pin down everything. It becomes a game of wack a-mo on both sides and usually it is only the innocent bystanders that get hurt. When you look at Battle Ground, who was really hurt? Do you think the Fomor were really set back that far? Yeah, the Ethinu was eliminated, but it is unclear if that got the king, I cannot remember, they didn't get Listen, they can come back to fight another day.. Namshiel is back in even a more dangerous and powerful form that he was as old Thorny. The White Council suffered some losses among it's Wardens, but the Senior Council is still in tact.. The Black Court made huge gains, as far as the dead Wardens now vamps go. Lara lost Thomas, but she gained Harry, Mab has more prestige.. So who lost? The people of Chicago, that's who, they suffered and more civilians are going to suffer, the Librarians cannot win the fight if they try to go after the supernatural world, it's too hidden, they don't understand it, and conventional weapons are pretty useless.