I appreciate you attempting to host these staff-sponsored events.
I don't think this event was as popular because we already have an arena in-game.
In my opinion, arenas and gladiator matches are boring, especially in this game where gear-score determines the winner more often than skill.
An event that I would like to see, would be to have a staff member take on the form of a giant monster and rampage a festival zone. Maybe a baby leviathan (controlled by a staff member) attacks a port city, killing everything and destroying trade until the beast is defeated.
Just an idea...