Wow that's a bummer, my friend always makes this out to be such and awesome event. I know he packed up and left Saturday night. You are right though, these types of events suck on the last day.
I don't know if you have ever been to the Turkey Run in Daytona Beach but it is the same way. Officially starts on Thursday (Thanksgiving Day) and runs through Sunday. From Weds-Saturday the place is just nuts, on Sunday you might as well not even bother as the place is a ghost town...