Presuming the allegations are true, I find it interesting that it went unaddressed for so long.

Multiple German politicians have been forced to resign decades after their dissertations, with similar accusations. It seems like it is a case of rising to a point of public renown that then leads to greater public scrutiny. In some cases, I wonder if it a fake-it-until-you-make-it situation that upon making it, causes the house of cards to collapse.