'Batman v Superman' broke records at the box office. But that doesn't justify its existence.

Before Warner Bros. gets too carried away with the record-breaking box office take of "Batman v Superman: Dawn of Justice" over the weekend, the studio might want to take a breath. The grim, galumphing behemoth has earned an admittedly impressive $424 million since Thursday, $254 million of it in overseas markets. But many observers estimate that "Batman v Superman," which had a combined production and marketing budget of about $400 million, will need to earn at least $1 billion in order to brea...