Maybe it's not the organizers, but the attendees are exhibiting self selection bias? Maybe males have a stronger urge to seek reputation/fame, so are more likely apply to conferences?

https://en.wikipedia.org/wiki/Self-selection_bias

That's a perfectly possible reason! So, as a conference organizer or attendee, do you want talks from people who seek reputation and fame, or do you want the best speakers?

Oh, I see. Is it really true that organizers filter out some part of the demographic, or are women due to bad experience not trying to present? I didn't organize a conference, so this is a serious question.

I mean, encouraging everyone to attend, submit talks, and ensure they all feel welcome and safe is more useful than making it seem like women (or some_x) are only at a conference due to maybe a diversity quota.

I think part of the problem is that for (most) tech conferences the current attendee base is skewed highly male. Current attendees become confident of the conference style and then go on to present in following years.

It's like the argument, and I'm forgetting which well known tech figurehead made this, but... "We don't need more girls in CS majors, we need more girls playing around on laptops in the summers of elementary school [to put them on a more level playing field with male counterparts 10–15 years later]."

The same problem exists in some societies' failure to accept male teachers in elementary school or kindergarten. The diversification experience of armed forces might provide valuable insight.

Conference talks magnify the usual biases. On the internet, nobody knows that you're a dog, but there's no way to avoid it when you're in person in front of hundreds of people. If you pick a mechanism involving speakers self-selecting (either literally an open CfP and no attempt to encourage people to submit, or encouraging people you know are good speakers to submit), you'll see the results of past biases.