I'm not sure that's entirely true, but they certainly didn't originally expect to be paying until folks were 90.
All of my grandparents made it to beyond 90. My mother is almost 93 (and I'll see her this weekend with a six year-old great-granddaughter). My father (two pack a day smoker since he was a teen) died at 73. I doubt he ever spent more than three weeks total in his life in a hospital, and probably most of that was paid for by private insurance. The Feds made a bundle on him.
ML/NJ