No, that's not what it assumes. It assumes that only men are capable of fixing the "boys club" attitudes. And that is spot on. A big part of the problem—and the part that is most easily addressed—is what happens when women are not around. Men need to take responsibility for fixing that.
The language of "responsibility" isn't the correct way to frame it though. I'm not "responsible" for corporations that pollute heavily, but I'm still going to argue against it in order to improve the world for future generations. I don't see how this is all that different.
Yes, that is why I charge all of us men with "policing" each other. The non-violent of us should be trying to get the violent of us unlearn the ideologies that justify the violence. It is men who maintain the culture and benefit from it, and it is women who lose, every time.
The problem is that when a man is accused of harassment, assault, or rape, that man is usually in a position of power and defended, while the woman is usually blamed, discredited, or otherwise attacked. Many women choose not to speak out because of the negative effect it can have on their career and their peer group, to say nothing of the onslaught of harassment that usually follows. It's much more necessary for society to change its thinking about women who report these actions than it is for women to report them, at this point. Women have been doing it, largely against their own self interest, from the beginning.
I'm not implying that women have been derelict in calling things out. I'm just saying that we should continue to encourage women to come forward with these types of abuses.
It's also not strictly necessary for women to report harassment in order to fight against it. Men can create a culture where harassment is unacceptable. Instead of joking about how hot Sasha Grey is, or how you want to fork a repo with a big dongle, we can talk about how fucked up it is that women are constantly groped and belittled. We can look for patterns of violent, misogynistic behavior in our peers and call them out on it. If we ourselves see harassment or sexism happening, we can step in appropriately. We can take women seriously when they do report it (something like 1% of rape accusations are false, for example). Harassment occurs because men have the power in society, and it's therefore incumbent on us to use that power to stop it.
Many men are good at this, but many more deny that there's even a problem. This thread is great evidence. Take a look at which comments are grey and which ones are still black; it's pretty clear how SV thinks about these issues. If you need more proof, find an Ellen Pao thread, same story there.
I agree with the comment above that the sorts of men who harass are the types that won't listen to complaints from women - so it's necessary for men to speak out about it. In addition to that though, the culture won't change until we shine a light on the abuses that do happen, and given that these are often private conversations, we need women to speak out when they're harassed as well, if we hope to accomplish anything.
It isn't a question of responsibility. It's about all of us, men and women working towards creating a better workplace culture, where this kind of shit doesn't fly.