It's not crazy, no one thinks that. My question is why do so many people think of and fear this as a plausible scenario, to the point they prefer to rot and die than see progress in that front. Now this is crazy.
So you might have doddering 120 year old ancients (potential predicted life extension) with ever more brain damage.
How would I be able to enforce it? By somehow keeping the costs high? By lobbying?
Nothing would work, because this would be too big for the working class to just sit there and watch, and if lots of people get really pissed, it can turn very ugly, as history has taught.
People will want it and they'll get it, one way or the other.