It was a valid observation

On Niall Ferguson: Why Did Keynes Write "In the Long Run We Are All Dead"?:

Likely Keynes meant it as a rhetorical trick, but it matters a lot, longevity is a major calculation in economics, real or models. Most of us face the unfortunate, it effects our planning and as the unfortunate gets closer we care less about the followers.

The unfortunate  also limits the viability of bonds longer than a career length, 30 years. These long bonds must be contained by the ability of the career bound salaries, longevity is a major part of the fit. The long run of the boomers is a major economic tipping point, and so on.