As Dan (Grumpy) & dynoman noted, the event this year was scheduled for the days leading up to and including Memorial Day Weekend.
For some this is a time dedicated attending memorials and services for those who gave all.
For others, considering lack of paid time off from work, it is family time for a get-a-way vacation, picnic, bar-b-que, etc. Nothing for the wife/girlfriend and kids to do while you BS with the boys about these black cars.
With the Elon college graduation ceremony the same time and the holiday, the area hotels have been fully booked for many, many months. What vacancies remained a few months ago were priced at double and triple the regular room rate. Most folks certainly will not pay $350+ a night for a room that is regularly $100 - $130 a night.
@SGRIM, so who are the 6 confirmed vendors? three weeks to go, maybe there will be some last minute confirming attendees.