If there's one cure that's worse than the disease, it's telling women to "cover up," like they were the fucking Elephant Man. The best example of this is another convention, a video game one in this case. Even if it was outside the context of the sheer moral-authority-forfeiting hypocrisy of banning displays of the female body at a video game event, there is in principle just something singularly offensive about demanding that women dress a certain way. Maybe it's because telling them to cover up reinforces the tiresome message that women in particular are responsible for how others act toward them. Maybe it's because it assigns women the responsibility for dealing with the fact that assholes have decided that the female body = sex, and instead of addressing the actual problem, it's instead just PUT A SHEET OVER YOUR NATURAL SHAME. P.S. THINK OF THE CHILDREN.
Maybe it's the fact that you're not instead going around telling assholes to cover up their huge, naked immaturity. Maybe it's because you're taking the same strategy you would in designing characters for comics or video games and applying it to real people, except fictional characters are a representation of how you choose to see people or wish them to be portrayed, whereas real people get to do their own choosing, because nothing is more sexist than denying someone the right to choose, regardless of what that choice may be. Or maybe it's just that enforcing a dress code is the hallmark of places that treat women like subhumans, and when you tell women to cover up, you evoke that and only that, and you are wrong to do it and your mouth should be covered up.
Very little makes me more pissed off than gender prejudice, but what do I ever do about it? Pretty much I just assume I'm not part of the problem, so enjoy your hive of scum and villainy, everyone, I live on a higher plane. And here you have by far the worst response to sexism: nothing. The response of choice of we who love avoiding confrontation (and comment section shitstorms). And so transgendered people continue to be disproportionately persecuted because not enough people are ensuring a supportive environment, and women continue to get chased off Twitter because not enough people are ensuring a supportive environment, and rape victims continue to not be taken seriously because not enough people are goddamn ensuring a supportive environment.
The ability of the Internet to make it seem like there are more assholes than there really are is allowing such bullshit to run wild, and the people who do speak up get hung out to dry by the silence of others. Not enough of us are making it clear that this is the world of the majority and not the vast minority fringe group of idiots, and so the one shithorn talking in the theater ruins the movie for the other 76 people who are afraid to speak up. Peer pressure is what drives humanity. Why aren't there any women/men in certain industries? Because the absence of women/men there keeps the others away. But we can harness peer pressure for good, too, and remind sexists that they are alone in the room -- especially online, because a tidy neighborhood discourages crime, and this is a neighborhood that needs a lot of fixing up.
The best response to sexism? Having zero tolerance for these absolute wankers. And it can be done; the infrastructure is already in place. If we have the wherewithal to instantly arrest people for making Nazi salutes or to accost women within 10 seconds of removing their shirts, then we can similarly be on hand to call out anyone who thinks they can tell others how to fucking dress. People like me need to reduce the disparity between how opposed we are to sexism and how much we actively do to help create an atmosphere that's poisonous to it. If you're in the same boat, then let's do this -- let's actually be part of the conversation, because it works. Captain Picard himself has given the order, if that helps (IT SHOULD). Because doing nothing is not good enough, dammit. Not good enough.