I'll say this for the younger adult crowd in the healthy life extension community: you 30 year olds are too damn optimistic about future timelines for healthy life extension technologies.
The biggest concern for me--right now, anyway--isn't maintaining my body in a youthful state. While this is definitely a concern, I feel able to adequately take steps in this direction, and mainstream society largely facilitates and encourages this behavior with widespread access to information and products aimed at youth restoration and maintenance. While many of these products are dubious, and others have only minor effects, I believe in the bridge hypothesis expounded by Ray Kurzweil, Aubrey de Grey and others: Each generation of life-extending interventions need only keep me alive until the subsequent generation in order for me to have an effectively indefinite lifespan. And given that I'm 29 and as far as I know in good health, I believe that, barring an unfortunate accident, there is a good chance for me to stay biologically youthful for a long period of time. (And yes, as a backup plan I am pursuing cryonics.)
I can't fault Simon Smith - the writer of that piece - for failing to stand up and do something; he has achieved more than I in building a well-trafficked megaphone and watering hole for healthy life extension and other transhumanist ideas. But still, there is the undercurrent of complacency that I see in the writings of many of the younger set - that the future technology is sorted, on the way, and meaningful anti-aging technologies will arrive in time.
I'd be optimistic myself if a scientific healthy life extension infrastructure as dedicated, large and advanced as that for cancer or Alzheimer's research actually existed. But it doesn't, and the scientific and advocacy communities have barely even started on the long road to building such a thing. The process could have been started a generation ago, but it wasn't. It may not get off the ground this generation.
My point here is that widespread complacency will be an undoing for us all - it's a common failure mode for those who look towards a better future, but never manage to engineer it. Massive assignment of time and resources is required for the goal of healthy life extension in our lifetimes. Engineering this use of resources is a huge task in and of itself. But supporters become enthusiastic, overestimate the degree of progress and the number of people helping make a better future, and stop making their own contributions. That scenario repeated en mass would mean that no progress is made - that healthy life extension technologies will not become effective enough to reach actuarial escape velocity within our lifetimes. Thus, game over; oblivion or taking your chances with cryonics.