Dr. Doom got it wrong.The parade of economists and investors led by Nouriel Roubini predicting Greece's ejection by now from the euro zone failed to appreciate the resolve of European policy makers to protect their union and the amount of pain Greeks are willing to stomach."People underestimated these factors," Roubini, chairman of New York-based Roubini Global Economics LLC, said in a telephone call 12 months after predicting Greece's exit in remarks to the 2012 World Economic Forum's annual meeting in Davos, Switzerland. A Greek departure "is certainly a less likely event this year, although not a zero probability."Joining him in questioning whether the 17-nation euro region was built to last and declaring Greece's departure imminent, inevitable or in its interest were hedge-fund manager John Paulson, Goldman Sachs Group Inc. President Gary Cohn, Nobel laureates Paul Krugman and Joseph Stiglitz, Pacific Investment Management Co. CEO Mohamed El-Erian, Kenneth Rogoff and Martin Feldstein of Harvard University, and Citigroup Inc. chief economist Willem Buiter.Roubini -- who earned his nickname for predicting the 2008 financial crisis -- as well as Cohn, Rogoff and Stiglitz are returning this week to the Alpine conference as investors pull back bets against the euro.That's a change in tone from a year ago, when German Chancellor Angela Merkel said Europe was "labeled the big headache of the global economy.""I am confident that the euro zone is broadly on the right track back to financial stability and economic strength," said Josef Ackermann, who stepped down last year as chief executive officer of Deutsche Bank AG, Germany's biggest bank.