I know it sounds ridiculous, and I'm not sure whether or not you meant this as a joke when you first wrote it, but this shit does happen. I've had one roommate who used to declare that women who spoke up for women's rights were feminazis and another who would use those sorts of grievances as a way to appear as a good listener and end up in bed with their tellers. </tangent>Right, because I'm a guy, and I'm the enemy, and because you know I'd use this as an opportunity to pick up chicks.
I was totally serious. At my school, at least, they held that rally two weeks into the Fall quarter. You barely know the kid you're sharing a dorm room with, half the "parties" you get invited to are some form of YoungLife or Christian Campus Crusade trying to convert you to Jeezus, you've somehow ended up with four credit cards (because hey - free T-shirt!) and they invite all the girls to come out to a thing that you actually support but you, as a male, better goddamn well stay away. It always seemed exceptionally cruel to me. I mean, what's wrong with "Hey, aren't you in my English class? Look at that! We're both against date rape! Wanna get coffee some time?" but instead the message is "all these men you're surrounded by are potential rapists. It's so bad we can't say this stuff in their presence, or even during the day. Watch yourself, girls, for there are monsters in the deep." Which meant the dorms filled with awkward conversations like this: "So... how was your... rape thing?" "Get away from me, male oppressor, I have a bra to burn." "Right. If you need me, I'll be playing Doom with my shitty Packard Bell speakers turned up to eleven."
Shitty people exist, but someone shouldn't be punished for having the potential to be a shitty person. Let someone's own words and actions define them.but this shit does happen.
I don't know that I'd call it punishment, though. There's a huge difference between calling an individual sexist and requesting they give you space to feel comfortable among your own gender. A public vigil may be pushing the grey area slightly, but if you think of it as an extension of women's circles, it makes sense.