I'll be totally honest, I have always found it very ridiculous and lazy from the writers' part, that since Wrath of the Lich King, during which Alliance first experienced and learned about the Blight made by Putress and the other biological weapons made by the Forsaken Apothecaries, that the Alliance didn't do anything to find weaknesses and counters to the Blight and other biological weapons whenever it's machines made by the Gnomes, spells or alchemical products able of neutralizing the blight, uses of light, druidic, void, fel or shaman magics as weapons to counter it.
What solutions do you think that the Alliance should have found in the long time it had to do researches and work on how to fight these biological weapons ?