(5000 per their announcements) The issue is not that the participation was limited, but that the number of people is knowable. You know how many people you have and can extrapolate the amount of food you need. Other large events manage to do it well.
As for the "party still going on" that's a common problem for these events. Particularly where you have multiple distances. Those who ride the century, and do it on the slower side, tend to miss out on all of the post-ride "fun". Nice to know people were still there for you.
I sent them an e-mail with a few "issues" I'll be curious to see if I hear back.
That said, there were some really nice touches. For instance, I stopped at 2 stop intersections the entire time. Cops would hold traffic and waive bikes through. Very nice touch. The dedicated ferries were nice as well. They also did a great job with the weather....