I think many, if not most, of these signatories are just generally opposed to AI usage rather than the basilisk of it all
I must admit that I signed this statement (before I discovered SneerClub) and I was definitely against AI usage as a whole (still am) but I also still think superintelligence shouldn't be built, because if we're letting Sam Altman and Elon Musk dictate the "values" encoded into it I do not want to live in that world