I think that the point is less to change it than to report on the fact that it's (still) happening.
If she just told him off and he avoided her for the rest of the night, but otherwise she still felt as isolated and ogled, how would that change things? If she picked up a megaphone and shouted about how she needed to be treated with more respect, would she be? Or would everyone just think she was looking for attention.
The way she conducted herself makes sense to me, and while she was put off by the situation, she still got most of what she wanted to out of it. She didn't go to the bitcoin meetup to make a stand on her rights, she did it to talk about bitcoins. While there, she was put off by the way she was treated. Had she just made a scene about the way she was treated, maybe she wouldn't get to talk about bitcoins, maybe the people there would think "Oh, ok, this makes sense. Women don't really talk about bitcoins, she's not here because she is interested in bitcoins, she's one of those feminists. I get it now."
Her blog post is just a way of expressing "Hey, I experienced some uncomfortable situations at a bitcoin meetup because I was one of two women in a sea of men who didn't take me seriously."
The thing is, it's not her responsibility to fix it. Sure, there's things that she can do, but when men go to a bitcoin meetup, they don't go there to argue for men's rights, they go to talk about bitcoins. She can't reasonably do both, and the only way women can get into bitcoins is if they talk about bitcoins. If they have to defend their gender position instead, they don't have much opportunity to do that.
The way to fix it is to support your female friends who are interested in these things to continue to be interested in them. To go with them, whether you're a guy or a girl yourself, to give them support when they are learning about them. To not make a big deal about the fact that they're a woman and you like these things. Instead spend your time just collaborating on those things that they're interested in.
The only real way it will change is when people start to see it as not unusual. The only way for it to become not unusual is for more women in general to get interested. If women are getting turned off these things by weird guys and sexist comments (which come about because culturally not many women participate in these topics), then you can either try and stop every immature guy from saying something sexist about a women who does things that no other women do, or you can support more women when they want to do those things so that can get something out of it even when the weird guys bug them. Maybe with enough women interested it will no longer be something that seems surprising.