I can on conscious level sort of understand that some people aren’t bothered by the fact that they’re gonna die, and can even sort of understand their reasoning (and I do believe in the right of people to make choices that I consider to be shitty), but on the intuitive level this is just incomprehensible for me. But then I remember that there are plenty of women who don’t just totally buy the idea that only young attractive thin women have value and deserve respect, and everyone else must be constantly shamed into “knowing their place,” but also enthusiastically and aggressively perpetuate it. That is despite the fact they’re basically guaranteed to sooner or later enter the category of people they worthless and deserving shame. And presumably the project of stopping appearance-based shaming or at least changing your own beliefs and finding yourself an accepting community is easier than eradicating death. So defending mortality makes at least as much sense - if not more - than defending old-unattractive-shaming, and evidently people can be extremely enthusiastic about the latter.
I’m definitely in the “death is preferable to no-death” camp, and while I can’t speak for others, I can maybe do a bit to try to explain my own position. The first thing I should emphasize is that “not being bothered by the prospect of your own death" and “in favour of mortality as a thing” are not as tightly coupled as you’re probably supposing. As with many issues, it’s often necessary to separate large-scale social policy from personal interests. It’s also important to distinguish between death by accident, trauma, or illness and death by aging, because they’re very different things. I don’t know anyone who’s against eliminating the former, but a lot of people (including me) are wary of tinkering with senescence. Futurist critics tend to frame this as a kind of superstitious nature worship, a slavish fixation on the moral supremacy of What Is, but I find that dismissal a bit too pat.
(cut bc long)
There’s more to it, but you even if you set aside the fact that not dying is actually very, very valuable, you also have to account for the disadvantages of the current system.
For instance, it is extraordinarily expensive to raise an entire generation of people, during which time they can’t really be part of the workforce without compromising their later effectiveness, have them work for a limited time as their bodies and minds slowly degrade, spend even more money as their bodies start to fall apart all at once, then discard them and bury their bodies.
Then we do it all over again. Only it’s worse, because they have to spend one quarter of their lifespan raising children to keep this going. This not only limits investment in children, but limits time in the workforce.
The stickiness of scientific theories might be related to health degradation and loss of neuroplasticity over time.
As for social change, I’m not sure that more is always better. We’re still wrestling with changes in incentives from the sexual revolution, and while LGBTs are only a small fraction of the population and were never a threat to society to begin with, polygamy has a lot more practical trouble associated with it (like decreases in the psychological health of women and children, and incentives that lead to very early or even child marriage) and is probably next on the Progressive schedule after Transgenderism, even though normalizing polygamy is probably not a good idea. (It’s different when it’s just a few nerds doing it.)