The Dining room seemed to get very little use during the convention, resulting to a huge crush into the Lobby Bar.
I suspect the issue was that it was a fixed menu three course meal, and while it was actually priced very well for a three course meal... I don't think a lot of people wanted a three course meal.
I do think people wanted a sit-down meal that wasn't bar food, but didn't want a starter and desert. (I was part of an expedition to the Airport to find one!)
Additionally, I think there wasn't enough signage to say "Hey, over here! This is a restaurant! There is food here!" and most of the time it looked empty and not being used so people weren't even checking the menu.