Am I saying that I can conceive of a time when smoking is no longer damaging? Not really; I was just illustrating that an unknown number of smokers would be gladdened to hear news that promised just such a possibility. For them, they would finally have a strong defense against the criticism and ostracism they endure, and give them some freedom to truly enjoy their smoke-breaks.
If there ever were therapies made available to undo the physical ravages of smoking, there will be a mass of [new] smokers who will welcome the news [but not necessarily ever sign-up for such a program] For them, just knowing it could be available is sufficient to neutralize their nagging fears that nicoharm might do them in eventually.
I offer in evidence the following: young smokers, when confronted with the threats of smoking related damage, almost to a woman, declare, "Ohh, but that's years away!! I'll quit by then & it won't matter."
But, of course, you are so right about the risks of smoking; their very palpable threat enhances the smoking appeal through the danger-thrill connection, just as you alluded to in your example of out amateur rock-climber.
On this message board, such a statement is like preaching to the choir.
I feel, though, that there are some other negative aspects of this adult-habit that paradoxically enhance the allure of smoking as well:
Bad Girl/Bad Boy rebels whose lifestyle are symbolized by the dangling cigarette, and who enjoy hedonistically w/o worrying about the blow-back or public opinion;
The rugged individualist who is aware of her/his imprint on society, but who dares you to challenge their personal choices [like smoking] because she/he has already achieved a personal stability and disconnect from society [I see entertainers, & highly creative souls here; artists, authors, sculptors, playwrights, composers, musicians to name only a few]. In a crowd of such as these, smoking is the norm & not the reverse [Dorothy Parker and the Algonquin Round Table].
True smoking will never be risk-free; I know that: but technology will certainly try to ameliorate the negative aspcts because there's money in there, somewhere. Big Money.
And risk-free smoking, if it ever surfaces, will be a very insipid varient of the smoking we all have enjoyed here through out our lifetimes.