I have a hard time imagining being motivated more by health than longevity -- I would don a cyber-suit that keeps me alive but elderly for a hundred years to be rejuvenated later.

The way we (people in general) use the word "health" is based on a concept of the body as a well-defined entity. It becomes less well-defined when there is a technological solution that is as unobtrusive to use as part of your natural body; for example, a tooth with a filling works pretty much just as well as one that never had a cavity to begin with, so we don't think of it as an ongoing medical problem.