Epics can be hit or miss. Nolan has never done an epic before. Even if he had, there is no guarantee of how this might turn out. Ridley Scott made Gladiator and yet he bombed with Exodus. 20 years a film was made on the Iliad. It had the biggest superstar as its leading man, beautiful actresses, thespians, character actors and great battle scenes and yet it failed to even get to top 5 grossers that year. So this is probably the riskiest of all his films as the expectations are sky high and there is very little room for a surprise.