>>279622428
Shortstacks combine two major feminine traits (Short height and big boobs) and squeeze them onto one character. This makes it hard for them to fit into the archetypes other body types generally have no problem with. Tall girls with big tits make perfect fem fatales, giantesses, villainesses, etc. Short girls with flat chests are good at illustrating innocence, elegance, or subverting expectations by being stronger than they look. (Tatsumaki for example.) However making a fem fatale 5 foot tall makes her much less threatening, and stacking massive milkers onto a dainty princess obliterates any grace or regality she previously had. Shortstacks don't fit into any archetype except "Manhandleable portable onahole that can feed my children". Therefore it is necessary to contain their power levels if you don't want your audience to immediately see your work as an Asanagi porn doujin. Hence why shortstack proportions get less dramatic the less ecchi a series is trying to be.