I just now stumbled on this article about Joe Kennedy Sr and how he supported Nazi while Ambassador. Joe Sr ruined his family. That is why they were “cursed” IMO
Joe Kennedy was recalled because of his coziness with Hitler and his minions. But, just as bad, is what he did with his own daughter — Rosemary. He had her lobotomized and turned her into a vegetable that had to be institutionalized for the rest of her life. He didn’t even visit her. And he never told Rose what he had done.
The "curse" came from the lobotomy that Joe Sr. had performed on his daughter Rosemary. The account of the procedure is just ghastly. A normal-functioning albeit rebellious young woman was rendered a total vegetable on the operating table.
Rosemary would be the first of Joe's children to die naturally, outlived only by her brother Ted.