Because Keynes didn't use his position to blackmail people regarding their sex lives while concealing arguably deviant behavior of his own?
There has NEVER been a shred of credible evidence to support such claims.
These were unfounded lies and rumors propagated by the left, because Hoover exposed their sorry asses. He exposed them as anti-American, Marxists, Communists, and sexual deviants.
Why did all thes rumors only surface after his death? It is easy to smear a dead man. He can't fight back. The sorry arse left also knew Hoover had no living relatives to come to his defense.