Here'* the why:
All of this was set in motion with Einstein’* death in 1955. Under the terms of his will, his estate eventually went to the Hebrew University of Jerusalem (HUJ), where he had been one of the first governors. Long after his death, new laws in the United States gave the university exclusive postmortem rights to profit from the Einstein name and image and the control of the Einstein “brand.” To represent its interests in Einstein’* commercial worth, the university worked with The Roger Richman Agency in Beverly Hills, whose mission was to protect the estate interests of such legendary figures as the Wright brothers, Rudolph Valentino, and Sigmund Freud. Einstein was in excellent company when, in April 2005, Richman was purchased by Corbis, a photo agency founded and owned by Microsoft’* Bill Gates.
Can it get any stranger? He was a celebrity and his name and likeness are protected just as much as Elvis, Disney characters, and even the Dalai Lama.