Because it was about sex?
No. Because the early 1970s were a different time. Most of us never had cause to believe that the major media lied or covered up or took sides. This was a time when we (or me, anyway) really bought their story of the camelot/St John F. Kennedy myth and they portrayed Richard Nixon as the first president in our lifetime who was touched by scandal.
Compared to the dirty tricks of the LBJ administration (which the WaPo knew about), Nixon was a saint.