Bob, I don't think whether a show review is done or not done has anything remotely to do with sales, attendance or anything related to such.
I has to do with the amount of time and work required to do a good review especially the ones which include both photos and good commentary.
Most folks go to knife shows to enjoy themselves. It's much harder to enjoy oneself when you are shooting dozens of photos and taking notes on what's going on. Then when you get home the real time consuming effort begins. There's down loading your photos, re-sizing/editing, identifying them, loading them up on a photosite (which can be a real pain in the ass) assembling them in a logical post order, transposing your notes into something resembling a informative, interesting and factual commentary, and finally posting ALL those photos. Then if the reviewer uses the professional show photographer's (Eric's, Coop's, Chuck's, Terrill's) "knife photos" (as I like to do) then there's the communication in getting permission and receiving the photos from the photographer then duplicating the time/effort I described for your own photos.
Ask Murray White how long it takes him to do one of his outstanding "show photo reviews"?
Bob, look at my last two show reviews and guess the hours involved.
Larry Bailey's 2009 Ohio Classic
http://www.bladeforums.com/forums/showthread.php?t=687328
ABS Expo 2009 San Antonio
http://www.bladeforums.com/forums/showthread.php?t=670827
I believe the people who have typically been doing them are just getting "burnt out". We need some new folks to step up to the plate and carry a camera to shows.
I've seen your posts in several threads on a couple forums lately questioning why we aren't seeing good show reviews done, so though I would give you my opinion.