Those that did not attend the Vintage Cup shoot years ago bitched that they had to pay admission, even if they did not shoot. If you signed up for one event and prepaid, you got in gratis.
How many guns shows are free? I don't know what it costs to have the tent put up, or rent a hall for a show, but it isn't cheap.
The success of these shoots is having shooters shoot, and vendors there to look at their merchandise. As was stated earlier, a shoot without vendors is just a shoot.
A successful shoot needs shooters and vendors. And the vendors need purchasers. Maybe the buyers just aren't buying