You seemingly are portraying people who worry about long term risks of ai as members of a religious cult. But you also acknowledge that AI could end humanity? The question of why AI would want to kill us has been addressed by other people before, simplified: your atoms are useful for many objectives. Humans use resources and might plot against you.
> You seemingly are portraying people who worry about long term risks of ai as members of a religious cult.
Strictly speaking, we can limit that to people who rearrange their lives around reacting to the possibility, even in sillier (yet not disprovable) forms like Roko's Basilisk.
People who believe having a lot of "intelligence" means you can actually do anything you intend to do, no matter what that thing is, also get close to it because they both involve creating a perfect being in their minds. But that's possible for anyone - I guess it comes from assuming that since an AGI would be a computer + a human, it gets all the traits of humans (intelligence and motivation) plus computer programs (predictable execution, lack of emotions or boredom). It doesn't seem like that follows though - boredom might be needed for online learning, which is needed to be an independent agent, and might limit them to human-level executive function.
The chance of dumb civilization-ending mistakes like nuclear war seems higher than smart civilization-ending mistakes like gray goo, and can't be defended against, so as a research direction I suggest finding a way to restore humans from backup. (https://scp-wiki.wikidot.com/scp-2000)