Not enough explanation in Wikipedia.
I'm "Silent" Generation, because I came of age in a Cold War period when to criticize the Government was thought to be unpatriotic - and dangerous. I remember watching the Army-McCarthy hearings on television; I remember the movie and TV blacklisting of writers, actors and directors; and I remember J. Robert Oppenheimer, the architect of the Manhattan Project, losing his security clearance because he was insufficiently enthusiastic about developing thermonuclear weapons.
Boy, those were the good old days.