>>25558711Way I see it, it's because gasmasks are one third badass, one third mystery, and one third danger. Someone in a gasmask is someone who's hiding something, but at the same time travelling/living in a dangerous environment. You know there's a human being behind that mask and some parts of it are human in appearance (eyes and a mouth), but at first sight gasmasks have an incredibly alien look and de-humanize whoever's wearing them. So there's mystery, but at the same time there's a certain degree of knowledge of what's behind that mask, so it's not as unnerving as a completely alien creature.