I agree. I was at AXPONA and mostly didn't expect that great of a sound (in fact, I was in Chicago mainly for another event that weekend, otherwise I might not have come). I came to the show mostly just for curiosity and to meet with friends. I did have high hopes for a few specific rooms, which partially lived up to expectations or even exceeded them.
I was pleasantly surprised to actually find some good sound elsewhere too. If the sound is good, that's a positive learning experience. If it's not good, I don't necessarily judge. But exhibitors should not expect such an attitude from most visitors of a show.
The most useful obviously is listening to other people's systems at home, which I do. They have had the time to optimize the sound over months or even years.