5) status quo bias.
Most people will change they minds the moment the technology is available and cheap. Or rather, they will keep disliking the idea of ‘immortality’ while profusely consuming anti-aging products without ever noticing the contradiction, because in their minds these will belong in two different realms : grand theories VS everyday life. Those will conjure different images (ubermensch consumed by hubris VS sympathetic grandpa taking his pills to be able to keep playing with his grandkids). Eventually, they’ll have to notice that life expectancy has risen well above what was traditionnally accepted, but by then that will be the new status quo.
6) concern about inequalities. The layman has always had the consolation that however rich and powerful someone is, and however evil they are, at least they die like everyone else eventually. But what will happen when some people can escape death indefinitely ? It means that someone who has accumulated power all his life… can keep accumulating power. Patrimony will no more be splitted among heirs. IMO, people would be right to be suspicious that such a game-changing advantage would end up in the hands of a small super-rich class.
7) popular culture has always envisioned the quest for immortality as a faustian bargain. This conditions people against seeing life lengthening as harmless.
In the case of UBI, what is optimization from the viewpoint of the decision makers is freedom from the viewpoint of those concerned by the decision.
After all : money is needed to fulfill the basic needs of life in society. Without UBI, little people are forced to look for money on the job market, where they are perpetually reminded that they must prove their usefulness by joining a group of sufficient efficiency on the global market (a company).
On the other hand, UBI frees these people to pursue their own, possibly wildly creative goals, however inefficient these are deemed by others.
So I’m thinking : maybe freedom is a limited (and highly valued) goods. If some have leeway to apply arbitrary decisions, then necessarily others don’t. I need airplanes to be very reliable so that I can travel at my fancy. Freedom is based on top of reliability (which is equivalent to optimization in this context). Even at the individual level : I’m free to do what I want today because my body is highly optimized to obey my mental commands.
This idea seems to pervade your article (e.g. when you mention corruption as a typical sign of freedom), but it wasn’t really explicited anywhere.