> I mention it because if we classify it as default, not inherent, it means we can and should be doing something about it.
Should? You're assuming that mortality is a problem. Extreme longevity or immortality would certainly change the human condition, but it's purely speculative to think it would be better in some objective, widely-accepted sense. Not every "default" is something waiting to be fixed.
Eliminating the biggest cause of sadness and suffering (not to mention, economic loss) sure sounds like something that would be widely accepted as good. There's a reason why almost every religion offers some kind of afterlife.
There's a good argument to be made that the assumption of mortality is baked into so many things in our economy that it would break down if people suddenly started to live much longer on average. But that, again, is a default - some state attractor. Something we can try to work around.
I respect your point of view, but I disagree with you. I suspect that people in general would be divided on the issue -- and the 'pro-death' faction (!) have not merely accepted, sheepishly, the limits of our existence without any reflection on the matter.
As a speculative anecdote, imagine spending ten thousand years missing a child who died in an irreversible accident. (Would childbirth even be permitted in such a future? How would overpopulation be addressed?) Or the dampening economic and sociological effects caused by a millegenerian population's entrenched resistance to change. Or the possibility that longevity is only available to the wealthy, or the drudgery of being stuck in a boring job for millenia...
Longevity doesn't necessarily solve sadness, suffering, and social ills -- it just shifts the goalposts.
Should? You're assuming that mortality is a problem. Extreme longevity or immortality would certainly change the human condition, but it's purely speculative to think it would be better in some objective, widely-accepted sense. Not every "default" is something waiting to be fixed.