There's evidence among humans that problem solving can be decoupled from having a functioning long-term goal system (i.e., autistic savants, certain types of frontal lobe damage, etc). So I think it's possible to create a 'dumb' problem solver that won't form any nefarious goals (or any goals) and would be overseen by humans. Furthermore, I think Nesov is wrong here; creating robust institutions and social stability, curing disease, etc - the elements of "saving the world" - fall under technical problem solving just as much as uploading, nano tech, protein folding or whatever. Advanced tech is inclusive of world saving.