plenty of AI researchers have already found out that 'I'll just write it and see if it works' tends not to generate human-level intelligence

I've noticed. But the failure of hacking does not imply that its opposite must succeed, and it's been enough years since the "AGI" phrase was invented to start passing judgement on the new wave's achievements. Most writings on mental architecture look like word salad to me. The mathematical stuff like AIXI is all very well as mathematics, but I don't see any design coming out of it.