Well it's ridiculous because it's not about healthy people living longer instead of "conveniently" dying off for the good of society(!) - it's about healthy people (of any age) not requiring all kinds of expensive medical care BECAUSE they are healthier.
It's about a 60 year old in excellent health NOT using up the "resources" of our society, as opposed to an out of shape overweight inactive 60 year old with clogged arteries who has heart attacks and diabetes and high blood pressure etc etc. and requires all kinds of medical services and hospitalization and nursing to be kept going and becomes totally disabled by their conditions. Who uses more "resources"?