I wasn't there but wasn't Superman: The Movie a major event at the time too? So, i made a list of the Blockbusters of 2013, tell me if i'm missing something:
-Gangster Squad
-Oblivion
-Jack the Giant Slayer
-The Great Gatsby
-Oz: The Great and Powerful
-Star Trek Into Darkness
-Iron Man 3
-Fast and Furious 6
-The Hangover 3
-After Earth
-A Good Day to Die Hard
-The Man of Steel
-World War Z
-The Lone Ranger
-Pacific Rim
-Elysium
-Monsters University
-The Wolverine
-Ender's Game
-The Hunger Games: Catching Fire
-Thor: The Dark World
-The Hobbit: The Desolation of Smaug
The Copycats of 2013: The White House Trilogy:
-Olympus has Fallen
-G.I. Joe: Retaliation
-White House Down
Well, it's a bigger list than i expected, i'm counting with films that were not released in the summer too. If i forgot any film or added one that i shouldn't have then tell me, if it's complete then i'll try to do the 2012 list next.
I wish they made more films like that, there is District 9 for example, there was also that one with aliens that people expected to be the next district 9 but failed critically.
If Star Wars was first released now it would probably fail very easily, a film like The Lone Ranger and last year's John Carter would be big things if released years before, when more people went to see Disney movies due to the brand alone.