I feel conflicted about this particular story. On the one hand if the con has set up a dress code that attendees must abide by, well then it shouldn't be surprising when they tell you to leave or change if wearing something that goes against the dress code. On the other hand I find it bizarre that the model was outright banned from the con for the next two days. The con runners could have given her the opportunity to change into something more acceptable by the dress code, but instead tell her she isn't allowed back in for the rest of the con, which to me seems unfair. As well as not giving her a second chance, the onus of the costume isn't on her but the company she was modeling for (assuming that it is the company that provided the costume, which seems to be the case). If the company is showcasing at a con, then it is their duty to talk with the con runners to figure out what parts of their showcase is suitable and what isn't. The con runners should have complained at the company running the showcase instead of the model, since for all intents and purposes the company either didn't know the costume wasn't appropriate (in which case the company wasn't diligent in determining what was and wasn't appropriate) or they knew the costume wasn't appropriate (in which case the company knowingly screwed the model over).
In regards to the model's outfit, it makes me wonder what the con's guidelines are. Sure it's a little revealing but a) not as revealing as other cosplays out there and b) not as revealing as some modern fashion. I guess it's a little stricter there then other places, can anyone confirm?
To also give a quick rundown on the my opinions on boothbabes: if your booth has representatives that can give you info on the game and also happen to look like characters from the game (even if it's a little revealing) I honestly don't see a problem with that, and can't think of many arguments to ban that type of marketing. If your booth though has simply women there to look good, I just don't care. If it actually attracts a larger demographic then fine, whatever works I guess, but chances are I'm not going to the booth SOLELY for that reason and would care little about whether that type of marketing is banned or isn't banned from a con.