As the person who does Sakura-Con's Cosplay Chess games (yes games), it takes a lot of work to plan scripted games. I do two of them. So, I'm working all year round, that's with my assistants.
So, it makes the most sense for Jaki to do an unscripted game because of her duties as the Director of Programming. A lot, lot, lot of work goes into even that game. Picking pieces, placing them, choosing Chess Masters. Trust me when I say that by the end of Sakura-Con, all I want to do is crawl underneath a desk and hide for a week.
Yes, there were things that could have gone better during the game. But, it's a learning experience, it always is. That's one thing that I enjoy about Kumoricon's game. It's unpredictable. But with Kumoricon the size it is, the unscripted game makes sense. The larger the convention (at least I've noticed) the more serious the games are.
At least Kumoricon isn't trying to do what Metrocon does. They script everything and only locals can participate in the game.
It takes work from both the participants and the audience to make a game run smoothly. So, please remember that when you're sitting in the audience next time.