Why? Those aren't the things I'm actually worried about, and those aren't the only "doomer" ideas, just the most extreme ones (thus easy to straw-man).
My main worries are about economic disruption, social damage due to the pace of technological change outpacing human ability to manage it, further concentration of power into small elites (along existing lines), and the reallocation of labor towards less personally-fulfilling pursuits.
I also totally buy into the idea that "AI leaders" are playing up certain risks as a marketing strategy. After all these are smart tech people, and those types have a tendency to get really arrogant and be irresponsible.
So the main thing is to slow all this down, so there's a chance of getting it under control, and snatch the payday away from such greedy and irresponsible people.