MetLife announced last week that it wants to sell its mortgage banking business, but regulatory and legal issues that are partly driving the firm’s retreat may also make it hard to find a buyer. Nowadays, starting from scratch may make more sense than buying someone else’s problems. MetLife explained in a press release that the decision was prompted by an “uncertain marketplace and regulatory environment [that requires] a tremendous amount of resources – both in terms of people and capital – to effectively compete in and profitably grow the forward mortgage business. Doing so would divert these resources away from...