As an avid convention goer and someone who has worked in the cosplay scene for countless conventions, let me preface with this...

She's either never been to a convention or is absolutely full of shit.

First, most conventions have guidelines that are far less strict for women than men. Christ, the whole "BUT LOOK AT WHAT THE GUYS ARE WEARING!" argument...I have seen women wearing 1/3rd of the fabric they are and ARE allowed to do so. Countless times. At almost every single convention I've worked with. In fact, women can wear the most revealing bra-like tops but a man going shirtless instantly gets asked to go up and put a shirt on.

Female cosplayers consistently get more freedom in outfits and attire than men do. The Nigri example? PAX is notoriously family friendly in those instances and she was a cosplay guest. They also are anti-booth babes. Guess what Nigri was there to do? So she was violating the policy they had in place, something you can find if you look it up, even on...SURPRISINGLY...FUCKING KOTAKU.

http://kotaku.com/5900134/skimpy-outfit-gets-lollipop-chainsaw-cosplayer-asked-to-leave-pax

"Penny Arcade's Khoo clarified to us that she was asked to change or step off the floor (technically, to restrict her presence to a demo area inside a bus in the game's booth)."

She was working the game booth and violated the policy they had in place. She got asked to change or stay off the demo floor. The guys in the picture there may be wearing less but they're not representing a company, they aren't violating any direct policies, and are still wearing more than thousands of women I've seen at conventions all throughout the nation. They're never asked to change unless they violate policies put forth, and normally still have a more lenient policy than males deal with.

But yeah. Sexism. Gaming industry. Whatever. You got it figured out.