I hate the idea of show organisers charging exhibitors and charging the public to view. (They are as bad as auctioneers)
But, I think there does need to be something in place to ensure exhibitors do actually turn up or at least encourage them to turn up, if they didn't have some form of incentive then if the weather was bad they may stay away and that wouldn't do anybody any good.
I wouldn't be against the organisers charging a lot more if they then refund it ALL after you arrive and stay until the show ended.
Wally