I have been to several shows, and I agree there are definitely a lot of very nice people (exhibitors, breeders, rescue people, etc.) at the shows. Most people are very friendly. However, it doesn't take too many people treating you like a second class citizen to make you kind of not want to attend another show, and I haven't been to one in 2 years as a result. I would be very reluctant to bring Daisy to a show now, after that experience. I would seriously feel like I had to bring her in on a covert basis straight to the cardiologist's room and then straight back out to avoid another experience like I had.
So, it's a very mixed bag. I've seen and chatted with some exhibitors who I think are wonderful people who love their dogs dearly (as I do), and I've seen other exhibitors leave their dogs on top of grooming tables unattended for long periods of time, which I do not like. At one show, I had my then 8 year old daughter with me, and the dog who had been sitting unattended on the grooming table for at least an hour and a half (the whole time that I was there) growled very seriously at her as she walked past! She didn't approach him or extend her hand to him or anything. She just glanced over at him and he growled at her. Didn't exactly fit the Cavalier personality, I have to say! I've seen friendly people and I've seen people who obviously believe that they are better than anyone in the room. So it's like anything else, there's the good and the bad and you have to decide if the good outweighs the bad.
As far as approaching any of the exhibitors, I know better than to do that before they go in the ring. At the show I mentioned in my original post, I was just sitting in the room with Daisy on a leash, watching the show ring when these comments were made. I wasn't speaking to anyone.
Anyway, I wasn't trying to dissuade any pet owners from attending a show because I have enjoyed several of them, but I was just relating a similar experience to the OP with the unsolicited comments about my dog that I didn't appreciate.