Conferences use valuable face-to-face time for worthless presentations by people who are not particularly entertaining

I recently made the point Dont give talks - hold conversations, so was deligehted to have since discovered a blog post How to Run a Good Conference from Aaron Swartz from 2002 where he says:

The problems with conferences come down to three things:

1. Speech is a bad medium for communicating information. 
2. Speech is a good medium for dialog. 
3. Get smart people and encourage them to talk.

He also makes the point that conferences get things backwards.

"They use valuable face-to-face time for worthless presentations by people who are not particularly entertaining and even if they were are saying things you already know, and then try and stifle discussion (one question per person, sir!) and shunt it off towards lunch or something (we don’t have time for questions now). Hello? What did all these people come out here for? I can watch infomercials at home just fine, thanks."

Exactly! Many conferences are becoming more conversational in their format. But what is the percentage that are still dreary death-by-powerpoint talks? I have no idea but putting a finger in the air, I would say about 95%, maybe higher.

When are conference organisers going to learn?