It was so cruel, because he'd managed to get his second son elected president, and then he could no longer walk or talk. He sat there and was told of JFK's murder in 1963, and then RFK's murder in 1968. He, who had always been a control freak, couldn't do a thing about it.
My personal theory is that was his earthly punishment for having his daughter Rosemary lobotomized.
A very interesting read is "I Hear You Paint Houses" the memoir of Jimmy Hoffa's hitman as told to a lawyer and published poshumously. He tells how mad Hoffa and the mob were about RFK going after organized crime, how he delivered hundreds in cash to Mitchell to get Nixon elected, and how a rifle was smuggled to Dallas.
And - lie down with dawgs, get up with fleas. He sacrificed his family for his own greed and lust. The Kennedy sons were all abused children.