I think there is room for critiquing conferences and events associated with peak oil, even if there tends to be strong disagreement with many or even all of the participants.

Ruppert I can do without.  I'm not sure he brings anything to the discussion.  Kunstler has merit as a critique of consumerism, but I do agree that there are many better representatives of the anti-consumerist viewpoint.

At the heart of peak oil is the idea of energy production, consumption, geology, physics, and economics.  That should remain the focus.  Kunstler should be playing a very very minor role in all this.  He's a critic of consumer society and suburbia.  That critique, in essence, can be summerized in a small paragraph.  And as an expert on energy, economics, or visualizing how society will deal with depletion, I think Kunstler brings nothing.  No real expertise--other than some ideas on how to redesign society.

Same goes for Heinberg.  A few ideas on sustainability living.  Nothing more.  They aren't experts.  But they've been able to build up a lot of frequenty flyer miles through their many speaking engagements.

Here's another perspective that is in agreement with the above post (shooting the messenger).  Part of my ad hominem discussion earlier is that one should, at some point, ignore certain aspects of a problem, including people.  It's just not discussed.  Don't even speak to it.  All the 9/11 stuff, for example.  One can easily say:  not discussed.  Geopolitics, fascism, etc, etc.  One can also easily say: not discussed.  Same goes for survivalism.  Join a survivalist online bulletin board to discuss survivalism.  It need not be attached to peak oil, and degrades the level of discourse.