CAMBRIDGE – At a closed-door conference attended by senior bankers, regulators, and some academics, Federal Reserve Governor Daniel Tarullo and Federal Reserve Bank of New York President William Dudley used their bully pulpit to do something unexpected. Instead of focusing on how to bolster bank stability – channeling more capital toward the largest institutions, curbing their riskiest activities, and determining how to manage a failing bank without bailing it out – the officials discussed the bankers themselves.