Some folk like this sort of stuff, but I can't help but feel that a certain degree of overthinking of healthy life extension takes place in some parts of the community.
Walker offers an interesting analysis, in which he defends longevity research against Singer's attack, even on the assumption that it would lead to an additional 70 or 80 years lived in less-than-optimal health. He points out that the available empirical studies do not support the idea that people are less happy in old age than at earlier times, despite inferior health. In fact, the happiness curve seems to be U-shaped: actually at its lowest point when we are in our late 30s or early 40s. (This may seem surprising, since that is exactly when we are at our peak in many ways, but perhaps that itself creates pressures which are not yet experienced when we are younger, and which start to recede as we move deeper into middle age. I'll avoid any further speculation about such issues.)
People should be free to cast their dispositions as they will, but really, aren't there better things to be doing in connection to lengthening the healthy human life span? Such as helping to make it happen in the first place? If that's not your priority, so be it, but I can't be the only one who thinks this world is possessed of a good deal too much talking and a good deal too little accomplishment. I'd be happier to see overthinking only in the ranks of opponents of healthy life extension - as that would be a good indicator that they aren't actually doing anything more than rearranging their tidy formations of words and concepts.
Yes, I am aware of the irony inherent in devoting a blog post to this topic.
From my perspective, there is a certain liberation in a simple view of healthy life extension that stems from libertarian principles. Your body is your own, and people should be free to associate in order to improve and lengthen their lives. Since no-one has any claim over your body and life, there is no need to justify yourself, your existence, and your choices with regard to longevity any more than you have to justify paying for rice versus potatoes for dinner. Hence utilitiarian pontifications for and against developing the technologies necessary to live longer are no more than light reading pieces for those who like that sort of material - not to be mistaken for anything of substance. Persuasion is rife in such a worldview, force absent. Those who wish to work on longevity, get on and do it. Those who don't, don't.
Now, if only we didn't live in a world in which government employees have the power to rip you from your life, suppress medical research on a whim, and otherwise make every private choice and collaboration a matter open to inference for anyone who can hold a purse to a politician's ear.
Think about that the next time you read one of these pieces on the justification for or against longevity research - that you live in a world in which you have to convince all other people that you be permitted to work towards living longer, because any one objector can efficiently shut down your efforts through the agency of government; an effort most would never undertake had they to fund it all themselves. This is a world in which every matter of progress and endeavor becomes a battle of snarling, ignorant, uninvolved crowds at the chokepoint of regulation and government power - in which truth is sacrificed for emotive argument, and resources squandered on fighting for the ability to progress.
This is a world in which progress towards advanced medicine and greater longevity is far slower than it might be, sadly.