I'm the last to defend fanservice in Skullgirls, but by asking "why" you're kinda implying that suggestive tones/artstyles are inherently negative, or involve artistic talent that could be invested in an objectively better way. Mariel and/or Alex were asked why they designed the characters and their animations "like this" before, and the answer was simply because they liked it like that. An artist doesn't need to be suffering when drawing attractive women, some enjoy it quite a lot.
why are we talking about this in the fanart thread though