Here's the key paragraph:
Structurelessness is often a means to perpetuate sexism, racism and class stratification. If men are socialized to be leaders and women are not, then it is not hard to imagine who would develop into leaders in a non-structured organization. A lack of structure provides no means of balancing those with certain privileges with those who are oppressed. We must create organizational structures that inherently guard against these forms of power imbalance.
And the preceding quote from Jo Freeman:
The idea of structurelessness does not prevent the formation of informal structures, only formal ones. A 'laissez-faire' ideal for group structure becomes a smoke screen for the strong or the lucky to establish unquestioned hegemony over others. Thus structurelessness becomes a way of masking power. As long as the structure of the group is informal, the rules of how decisions are made are known only to the few, and awareness of power is limited to those who know the rules.
There's an interesting parallel here to the current kerfuffle in the atheist movement. People, especially women, are speaking out about sexual harassment at atheist conventions, and advocating for explicit sexual harassment policies to be put in place. They're receiving a certain amount of pushback from the convention organizers and other attendees, especially men. DJ Grothe, the man behind The Amazing Meeting, accused the complaining women of spreading rumors and driving other women away from the convention, which sparked predictable (and justified) outrage among many people.
I think there's a clear reason why many atheists minimize or dismiss sexual harassment at conventions. The vast majority of religions are systems for keeping women oppressed, obviously. Atheists comment on this with commendable regularity. However, there's a temptation to go a step further and say that religion is the main or only system for the oppression of women - and that in removing religion, the primary vector for misogyny is removed too. Atheist conventions are theoretically religion-free, so they must be harassment-free as well. If women contradict this by reporting their experiences of harassment, then they must be exaggerating or lying. Those silly, hysterical women. Can't they see we're their allies?
Do you see where I'm going with this? The state is a vast system for keeping women oppressed (men too, but women slightly more so), obviously. Some anarchists comment on this with commendable regularity. However, there's a temptation to go a step further and say that the state is the only system that oppresses women - and that when the state is smashed, misogyny is smashed with it. Anarchists, then, simply can't be sexists. So there's no need to put in place sexual harassment policies in anarchist organizations.
Unfortunately, religion and the state are only lenses; focusing mechanisms which amplify the existing tendency humans have to oppress those weaker than us. A world without guns would be a world with less death, but of course there would still be a horrible amount of violence. Removing the mechanism is desirable, but it won't combat oppression by itself. Solving the problem of sexism is harder than many male atheists and anarchists believe. It's a task that is performed in the heart more often than the courtroom or the houses of government, and it's a task that forces us men to relinquish much of our own power, much of our own privilege.
Of course, IOZ got here long before I did.