I'm not sure that in reality the differences here are that great. We all have a tremendously human lens through which we view and experience the world, and some of the distinctions here strike me as pretty arbitrary.
Why should 'loved ones' enter into the causal reality (in order to motivate a desire to end death and suffering)? Why not view each person as equal moral agents with equal moral worth? Are flowers a gift of value that bring colour and scent, or are they decaying plant matter? It seems to me there's an implicit value set that's been smuggled in to the world of 'how things really are'.
Often, an argument from causal reality is not enough because arguments are themselves not enough. Often, I think it is a fine argument but I remain unconvinced because you are trying to convince me of something that I don't think maps to reality, but I don't have the ability, expertise, time or verbal skill to overcome your argument. The need for experts is a shortcut here for someone else who may have some or all of those components.
The passage quoted above seems to me to be the expression of the quite rational, Bayesian analysis: 'Death seems like a very fundamental component of life, we have had a very, very long time where this is so. How sure can I reasonably be that this paradigm will change within a human generation, even taking into my account the belief of the strong possibility of a transformatively intelligent AI?'
I think there's something here in this post- some people are absolutely more able to go against the grain. But I'm not sure this phenomenon is as strongly siloed as presented, not as clearly valuable as presented nor as unique to rationalism as presented.
I really enjoyed your description of prosecutorial discretion, and wanted to explicitly state that these conditions occur on a socio-political level constantly. There's no question that if the standard of prosecution for appropriate commentary on Twitter outlawed tweets from Sarah Jeong or James Gunn, then just about everyone is guilty, but simply haven't raised their profile enough against some adversarial interest to be worthy of prosecution.
It also seems to me that given the fast and evolving understanding of what is appropriate to say on a public platform, and the archival nature of the internet, it is inevitable that comments once deemed appropriate will slip into inappropriate and eventually outrageous over time, solidifying the ability for adversaries to find skeletons in our digital closets.