The idea of events as mini games or in a set building has been suggested before and shot down. I think the biggest hurdle with it is of course the reward system and making it non abusable. They would have to set a lot of limitations on it and in the end I think it would probably be a lot of work. Which we all know that admins are not fond of. So it is a lot easier for them to run events randomly during their "free time" instead of investing their time in making something like that.
The one thing I like about that idea is the potential to incentivize players into at least congregating into another area taking away some of the idlers in Graal city....maybe