Why? Retirement is a very recent phenomena. The idea of someone earning enough during their working life to then fund several decades of non-working life is a very modern thing, maybe only the last sixty years or so. Only a very rarified few were ever wealthy enough to actively stop working prior to becoming physically unable to work. And then, for most all of human history, those too old to work lived out their remaining few years being taken care of by their children. I'm would not casually assume any "right" to the modern concept of retirement.