I don't get it

Really? Because authority figures have, you know, authority. I mean, standing up for yourself is a fine thing to do, but there's a limit to what you can do as a random attendee, and I don't see how it'd be some moral failing to ask the organizers to do their damn job. If someone is harassing people, the appropriate response is to kick them out, and I can't do that, but the conference organizers can (and should). Or would you prefer, like, some sort of vigilante justice?

The fact is, in a conference setting, some people have more authority than others. So those people have to make a choice. They can use that authority to back up the jerks (e.g., by egging them on from the podium or just ignoring legitimate complaints) or to back up the non-jerks (e.g. by kicking out people who harass others and not inviting them back).

And the nature of authority is that whichever option they pick is likely to have much more of an effect on how the conference turns out than whatever I do. So in practice, telling attendees that they should stand up for themselves and stop whining means (1) you're saying that it's okay for people with authority to back up the jerks, and (2) it's the responsibility of individual (female) attendees to take on not just the jerks, but the whole conference apparatus.