[behindsight]

Apologies if I misunderstood, but I don't think that particular point was missed; it seems to be the article's first stated viewpoint actually:

> the narrative I got was fairly clear: we didn’t use chemical weapons because after World War I the nations of the world got together and decided that chemical weapons were just too horrible and banned them, and that this was a sign of something called ‘progress.’

That point is even further iterated on in the conclusion when comparing them to cluster munitions which as you put, "cause multi generation effects" due to remaining active years after the conflict.