@runrin
Well to be fair people tend to be more trusting of kids and more likely to ignore them compared to adults. Or the designer had a loli fetish. Considering Japan I'd guess it is a 30/70 split between the two reasons. =P
Also if we want to get dark making a combat model look like a kid has some grim logic to it, similar to why child soldiers are effective. From what I understand most people, even trained soldiers, will hesitate more when it comes to shooting what looks to be a child even if their lives are at risk. As Isshin Ashina says "hesitation is defeat". I think it is the Lizard brain's "Don't kill offspring" instinct kicking in. I don't see the comic going that grimdark in explanations though. At least I hope not. *Puella Magi Madoka Magica flashbacks*