The purpose of the show is to attract visitors (ie. paying customers); me, I'm going to see what I'm up to on the day before I decide whether to go.
It does for sure require a big effort on the part of the exhibitors, and nobody is downplaying that; however, if there's little or nothing of interest then the case for going is not made.
There are people who are looking to plan ahead: book hotels, flights, plan weekends, so there needs to be stuff there for them.
So far I've not seen a "must go" item on the list so far; the nearest is Paul Gilbert, but he's also got a gig upcoming nearby to me, which I could go to instead.