To be fair, if you search for porn of Street Fighter or Guilty Gear or any other popular franchise, the number of artists that you find drawing porn will outnumber the number of people playing the game competitively. It's just life.
R34 of bigger fighters eclipses us. Street Fighter has live actor porn and theres knock off Ryu and Chun on condom packages.
Sure, they have more r34 crap, but my point was that the SG scene is so small that more attention is given to it's fanart, at least proportionally. Those games have a bigger player base, years of competitive play, and at least in SF's case, a real place in video game and pop culture that is wholly outside of whatever creepy fanart that comes from it. The game and competitive community keeps a shroud over that stuff to the general populace.
Compare this to Skullgirls, which already had a bad start with it's visuals, and that doesn't have enough of a "hey look at the actual gameplay" element,
AND was given a second chance via Indiegogo that was funded in no small part to SG art/lore fans. It's a situation that is just not comparable. We have a smaller voice in the FGC and at large, so whatever bubbles to the top gets heard by everyone, instead of having different channels for fanart, tournaments, YT producers, w/e.
Take Reddit for example, if I go to the top 100 posts of all time in the SG sub, I will find ZERO full gameplay cilps. There are only one or two Let's Plays, and just as many "funny moments" type of clips. The rest is art, cosplay, and 2-3 crowdfunding announcements. Compare this to the SF4 sub, which is a healthy mix of everything, art, gameplay, announcements, w/e. It doesn't matter if those bigger games have more casual art lovers than people who follow the competitive scene. The latter is big enough that it warrants it's own channels of media and viewership that they are seen as separate.
The look of SG has dominated the discussion about it from day one. Maybe in the FGC the talk was about the gameplay at first, but I don't believe it has ever been the majority conversation. It's a real problem that the art of the game brings, and I believe that r34 fanart only compounds this issue.