One thing about keeping sick people alive that financials don't cover - keeping up the social contract. A society must take care of its weak and old, unless you want these people to reneg on the contract and start being destructive. Marginalizing and neglecting a social group is step 1 towards fostering terrorism.
Yes... but not at unlimited cost. In a society with limited resources, is keeping one old person alive worth 10 child/years of education? Worth heart surgery for a 50-year-old? Worth basic medical care for a dozen poor families? Yes, the social contract says that we have to care for old people, including medically. It also says we have to educate children, and care for the poor, and provide medical care for everyone…
So reneging on the social contract with the old means reneging on the social contract with essentially everyone.
"Them" being destructive in response doesn't necessarily mean 85 year-olds burning things down, what it means is the 20, 30, and 40 year-olds seeing what's coming and burning things down.