After noting recent varieties of opposition to research likely to lead to longer, healthier lives - from Leon Kass and S. Jay Olshansky - I should say that it is good for advocates for healthy life extension and scientists working on healthy life extension technologies to engage their opponents. As Aubrey de Grey explains in a piece reprinted at the Longevity Meme:

The progress of ideas always has enormous inertia, on account of the emotional, intellectual and financial investment on the part of those who hold conventional views. Scientists, like others, find it difficult to write off that investment and embrace a new paradigm even when the argument for that new paradigm is very comprehensive. This manifests as a reluctance to consult relevant scientific literature, or even to entertain the idea that such literature is relevant in the first place. It also manifests as a preference for avoiding overt debate on such matters, since any such debate opens up the risk of being forced to acknowledge the superiority of the new paradigm. None of this is conscious, but it is a very powerful force opposing progress. In this case, the idea that reversing aging might be easier than slowing it down a bit is so counter-intuitive that many of my colleagues are inclined to dismiss it out of hand before taking the time to look at my argument in detail.

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Scientists prefer to promote and discuss what they are working on. They aren't so keen to tell people that they would be working on something altogether more interesting or ambitious if only their funders had the imagination and courage to sponsor it, because that's a quick way to lose funding. Now, you might ask, why are funders so unambitious? In industry it's because of the dominance of short-term views: shareholders reward companies that can make money quickly and certainly with boring products, and so these companies will do so in preference to taking greater risks on ambitious products - even if the potential rewards are far greater. In the public sector, funders don't want to be perceived to be wasting taxpayer money on blue-sky work with no chance of success. So, the root problem here is the pessimism of voters. But, of course, that pessimism is due precisely to the public face that senior biogerontologists put on their research...

So people like Leon Kass and S. Jay Olshansky - who are prepared to debate in public to at least some extent - are far more helpful opponents for the healthy life extension community than the old guard in gerontology whose names do not end up in the press. Old, false (or just less useful) paradigms in science can only live on if their proponents avoid direct debate and the detailed examination of new ideas.